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Custovic A, de Moira AP, Murray CS, Simpson A. Environmental influences on childhood asthma: Allergens. Pediatr Allergy Immunol 2023; 34:e13915. [PMID: 36825741 DOI: 10.1111/pai.13915] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 01/19/2023] [Indexed: 02/15/2023]
Abstract
Allergen exposure is associated with the development of allergen-specific sensitization, but their relationship is influenced by other contemporaneous exposures (such as microbial exposure) and the genetic predisposition of the host. Clinical outcomes of the primary prevention studies that tested the effectiveness of allergen avoidance in pregnancy and early life on the subsequent development of sensitization and asthma published to date are inconsistent. Therefore, we cannot provide any evidence-based advice on the use of allergen avoidance for the primary prevention of these conditions. The evidence about the impact of allergen exposure among and among sensitized children with asthma is more consistent, and the combination of sensitization and high exposure to sensitizing allergen increases airway inflammation, triggers symptoms, adversely impacts upon disease control, and is associated with poorer lung function in preschool age. However, there are differing opinions about the role of inhalant allergen avoidance in asthma management, and recommendations differ in different guidelines. Evidence from more recent high-quality trials suggests that mite allergen-impermeable bed encasings reduce hospital attendance with asthma attacks and that multifaceted targeted environmental control improves asthma control in children. We therefore suggest a pragmatic approach to allergen avoidance in the management of childhood asthma for clinical practice, including the recommendations to: (1) tailor the intervention to the patient's sensitization and exposure status by using titer of allergen-specific IgE antibodies and/or the size of the skin test as indicators of potential response; (2) use a multifaceted allergen control regime to reduce exposure as much as possible; and (3) start intervention as early as possible upon diagnosis.
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Affiliation(s)
- Adnan Custovic
- National Heart and Lung Institute, Imperial College London, London, UK
| | | | - Clare S Murray
- NIHR Manchester Biomedical Research Unit, Division of Immunology, Immunity to Infection, and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, Manchester, UK
| | - Angela Simpson
- NIHR Manchester Biomedical Research Unit, Division of Immunology, Immunity to Infection, and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, Manchester, UK
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Lee DL, Baptist AP. Understanding the Updates in the Asthma Guidelines. Semin Respir Crit Care Med 2022; 43:595-612. [PMID: 35728605 DOI: 10.1055/s-0042-1745747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Asthma is a chronic inflammatory lung disease that affects millions of Americans, with variable symptoms of bronchospasm and obstruction among individuals over time. The National Heart, Lung, and Blood Institute (NHLBI) published the 2020 Focused Updates to the Asthma Management Guidelines based on the latest research since the 2007 Expert Panel Report-3 (EPR-3). The following article reviews the 21 new recommendations on the six core topics in asthma: use of intermittent inhaled corticosteroids, long-acting muscarinic antagonist therapy, use of the fractional exhaled nitric oxide test in asthma diagnosis and monitoring, indoor allergen mitigation, immunotherapy, and bronchial thermoplasty. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to rate recommendations as strong or conditional based on the evidence. The recommendations were based on systematic reviews of the literature and focused on patient-centered critical outcomes of asthma exacerbations, asthma control, and asthma-related quality of life. Understanding the recommendations with consideration of individual values through shared decision-making may improve asthma outcomes.
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Affiliation(s)
- Deborah L Lee
- Department of Internal Medicine, Division of Allergy and Clinical Immunology, University of Michigan, Ann Arbor, MI
| | - Alan P Baptist
- Department of Internal Medicine, Division of Allergy and Clinical Immunology, University of Michigan, Ann Arbor, MI
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3
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Cloutier MM, Baptist AP, Blake KV, Brooks EG, Bryant-Stephens T, DiMango E, Dixon AE, Elward KS, Hartert T, Krishnan JA, Lemanske RF, Ouellette DR, Pace WD, Schatz M, Skolnik NS, Stout JW, Teach SJ, Umscheid CA, Walsh CG. 2020 Focused Updates to the Asthma Management Guidelines: A Report from the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group. J Allergy Clin Immunol 2020; 146:1217-1270. [PMID: 33280709 PMCID: PMC7924476 DOI: 10.1016/j.jaci.2020.10.003] [Citation(s) in RCA: 402] [Impact Index Per Article: 100.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 12/22/2022]
Abstract
The 2020 Focused Updates to the Asthma Management Guidelines: A Report from the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group was coordinated and supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. It is designed to improve patient care and support informed decision making about asthma management in the clinical setting. This update addresses six priority topic areas as determined by the state of the science at the time of a needs assessment, and input from multiple stakeholders:A rigorous process was undertaken to develop these evidence-based guidelines. The Agency for Healthcare Research and Quality's (AHRQ) Evidence-Based Practice Centers conducted systematic reviews on these topics, which were used by the Expert Panel Working Group as a basis for developing recommendations and guidance. The Expert Panel used GRADE (Grading of Recommendations, Assessment, Development and Evaluation), an internationally accepted framework, in consultation with an experienced methodology team for determining the certainty of evidence and the direction and strength of recommendations based on the evidence. Practical implementation guidance for each recommendation incorporates findings from NHLBI-led patient, caregiver, and clinician focus groups. To assist clincians in implementing these recommendations into patient care, the new recommendations have been integrated into the existing Expert Panel Report-3 (EPR-3) asthma management step diagram format.
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Affiliation(s)
- Michelle M Cloutier
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Alan P Baptist
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Kathryn V Blake
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Edward G Brooks
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Tyra Bryant-Stephens
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Emily DiMango
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Anne E Dixon
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Kurtis S Elward
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Tina Hartert
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Jerry A Krishnan
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Robert F Lemanske
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Daniel R Ouellette
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Wilson D Pace
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Michael Schatz
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Neil S Skolnik
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - James W Stout
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Stephen J Teach
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Craig A Umscheid
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
| | - Colin G Walsh
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda
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Abstract
PURPOSE OF REVIEW To critically review the evidence in favor or against the use of house dust mite (HDM) allergen avoidance measures in patients with asthma. RECENT FINDINGS Systematic reviews and meta-analyses suggested no positive effect of mite allergen avoidance strategies on asthma outcomes, resulting in a lack of consensus regarding the utility of these measures. However, such analyses have a number limitations and might not be the most adequate tool to evaluate current evidence and to derive clinical recommendations regarding mite allergen avoidance in asthmatic patients. We should not disproportionately rely on the results of meta-analyses and systematic reviews to inform clinical practice and asthma guidelines in this area. Recent high-quality evidence from randomized controlled trial in children confirmed that mite allergen-impermeable bed encasings reduce emergency hospital attendance with acute severe asthma exacerbations. Until better evidence is available, we suggest that physicians should adopt a pragmatic approach to mite allergen avoidance and advise sensitized patients to implement a multifaceted set of measures to achieve as great a reduction in exposure as possible. Potential predictors of positive response (e.g., patient's sensitization and exposure status) can pragmatically be evaluated using the size of skin test wheal or the titer of allergen-specific IgE. Finally, the intervention should be started as early as possible.
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Affiliation(s)
| | - Adnan Custovic
- Imperial College Healthcare NHS Trust, London, UK.
- National Heart and Lung Institute, Imperial College London, London, UK.
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van Boven FE, de Jong NW, Braunstahl GJ, Gerth van Wijk R, Arends LR. A meta-analysis of baseline characteristics in trials on mite allergen avoidance in asthmatics: room for improvement. Clin Transl Allergy 2020; 10:2. [PMID: 31921410 PMCID: PMC6943957 DOI: 10.1186/s13601-019-0306-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/13/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Evidence regarding the clinical effectiveness of mite allergen avoidance for the treatment of asthma is lacking. In previous meta-analyses on mite allergen control, the baseline data were not discussed in detail. This study updates and extends the existing Cochrane review by Gøtzsche and Johansen (Cochrane Database of Systematic Reviews, 2008, Art. No: CD001187), with a focus on baseline asthma outcomes and allergen exposures. METHODS We used the existing trials in the original Cochrane review and included newly published studies. The baseline data for the mite allergen load from the mattress, the standardized asthma symptom score (ASS), the forced expiratory volume in 1 s percentage of predicted (FEV1 %pred.), and the histamine provocative concentration causing a 20% drop in FEV1 (PC20) were extracted. First, the mean values of the outcomes were calculated. The influence of the mite allergen load was examined with a random-effect meta-regression using the Metafor package in R. RESULTS Forty-five trials were included; 39 trials reported strategies for concurrent bedroom interventions, and 6 trails reported strategies for air purification. The mite allergen load ranged from 0.44 to 24.83 μg/g dust, with a mean of 9.86 μg/g dust (95% CI 5.66 to 14.05 μg/g dust, I2 = 99.8%). All health outcomes showed considerable heterogeneity (standardized ASS mean: 0.13, 95% CI 0.08 to 0.18, I2 = 99.9%; FEV1 %pred. mean: 85.3%, 95% CI 80.5 to 90.1%, I2 = 95.8%; PC20 mean: 1.69 mg/mL, 95% CI 0.86 to 2.52 mg/mL, I2 = 95.6%). The covariate mite allergen load did not significantly influence health outcomes. DISCUSSION This meta-analysis shows that mite avoidance studies are characterized by the inclusion of patients with rather mild to moderate asthma and with varying and sometimes negligible levels of allergen exposure. Future studies should focus on patients with severe asthma and increased levels of allergen exposure.
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Affiliation(s)
- Frank E. van Boven
- Department of Internal Medicine, Section of Allergology & Clinical Immunology, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Nicolette W. de Jong
- Department of Internal Medicine, Section of Allergology & Clinical Immunology, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Gert-Jan Braunstahl
- Department of Pulmonology, Sint Franciscus Vlietland Groep, P.O. Box 10900, 3004 BA Rotterdam, The Netherlands
- Department of Pulmonology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Roy Gerth van Wijk
- Department of Internal Medicine, Section of Allergology & Clinical Immunology, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Lidia R. Arends
- Department of Biostatistics, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Psychology, Education & Child Studies, Erasmus University Rotterdam, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands
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van Boven FE, Arends LR, Braunstahl G, van Wijk RG. A reintroduction of environmental mite allergen control strategies for asthma treatment and the debate on their effectiveness. Clin Exp Allergy 2019; 49:400-409. [PMID: 30659677 PMCID: PMC6850033 DOI: 10.1111/cea.13340] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 12/21/2018] [Accepted: 01/09/2019] [Indexed: 12/19/2022]
Abstract
Asthma affects three hundred million people worldwide. The effectiveness of house dust mite allergen control for asthma treatment is debatable. One aspect that has been little discussed in existing meta-analyses is the possible role of environmental strategies. Here, we reintroduce the previously defined strategies for mite allergen control and discuss their importance to the debate on clinical effectiveness. The strategy of concurrent bedroom interventions is related to the combined use of a priori defined interventions, while the strategy of exposure-based control relates to the treatment of relevant textiles after assessing exposure. The air purification strategy aims to purify the human breathing zone of airborne allergens. In Western European patient practice, the use of these strategies differs. A post hoc study of the dominant Cochrane review by Gøtzsche and Johansen (Cochrane Database of Systematic Reviews, 2008, Art. No: CD001187) appears to indicate that a majority of the underlying trials reported on the strategy of concurrent bedroom interventions, which were mainly executed in a minimal manner. Some trials have reported on the air purification strategy and may potentially alter the debate on effectiveness. No trial has reported on the strategy of exposure-based control. We therefore hypothesize that the absence of evidence for the effectiveness of mite allergen control for asthma treatment applies to the strategy of concurrent bedroom interventions. The evidence-based effectiveness of the exposure-based control strategy appears to be undetermined. The results of our post hoc reanalysis urge that future meta-analyses of mite allergen control should a priori define the environmental strategy under study. Future trials of mite allergen control are warranted to test the exposure-based strategy as well as the sparsely tested strategy of air purification.
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Affiliation(s)
- Frank E. van Boven
- Department of Internal MedicineSection of AllergologyErasmus Medical CenterRotterdamThe Netherland
| | - Lidia R. Arends
- Department of BiostatisticsErasmus Medical CenterRotterdamThe Netherlands
- Department of Psychology, Education & Child StudiesErasmus University RotterdamRotterdamThe Netherlands
| | - Gert‐Jan Braunstahl
- Department of PulmonologySint Franciscus Vlietland GroepRotterdamThe Netherlands
- Department of PulmonologyErasmus Medical CenterRotterdamThe Netherlands
| | - Roy Gerth van Wijk
- Department of Internal MedicineSection of AllergologyErasmus Medical CenterRotterdamThe Netherland
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Leas BF, D'Anci KE, Apter AJ, Bryant-Stephens T, Lynch MP, Kaczmarek JL, Umscheid CA. Effectiveness of indoor allergen reduction in asthma management: A systematic review. J Allergy Clin Immunol 2018; 141:1854-1869. [DOI: 10.1016/j.jaci.2018.02.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/16/2018] [Accepted: 02/02/2018] [Indexed: 10/18/2022]
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Affiliation(s)
- Stephen T Holgate
- Respiratory Cell & Molecular Biology Division, School of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK.
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Murray CS, Foden P, Sumner H, Shepley E, Custovic A, Simpson A. Preventing Severe Asthma Exacerbations in Children. A Randomized Trial of Mite-Impermeable Bedcovers. Am J Respir Crit Care Med 2017; 196:150-158. [DOI: 10.1164/rccm.201609-1966oc] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Clare S. Murray
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
- University Hospital of South Manchester, Manchester, United Kingdom
- Royal Manchester Children’s Hospital, Central Manchester University Hospitals National Health Service Foundation Trust, Manchester, United Kingdom
| | - Philip Foden
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
- University Hospital of South Manchester, Manchester, United Kingdom
| | - Helen Sumner
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - Elizabeth Shepley
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
- University Hospital of South Manchester, Manchester, United Kingdom
- National Institute for Health Research South Manchester Respiratory and Allergy Clinical Research Facility, University Hospital of South Manchester, United Kingdom; and
| | - Adnan Custovic
- Department of Paediatrics, Imperial College London, London, United Kingdom
| | - Angela Simpson
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
- University Hospital of South Manchester, Manchester, United Kingdom
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Roberts JR, Newman N, McCurdy LE, Chang JS, Salas MA, Eskridge B, De Ybarrondo L, Sandel M, Mazur L, Karr CJ. Integrating Environmental Management of Asthma into Pediatric Health Care: What Worked and What Still Needs Improvement? Clin Pediatr (Phila) 2016; 55:1271-1278. [PMID: 26647159 PMCID: PMC8221413 DOI: 10.1177/0009922815621033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The National Environmental Education Foundation (NEEF) launched an initiative in 2005 to integrate environmental management of asthma into pediatric health care. This study, a follow-up to a 2013 study, evaluated the program's impact and assessed training results by 5 new faculty champions. We surveyed attendees at training sessions to measure knowledge and the likelihood of asking about and managing environmental triggers of asthma. To conduct the program evaluation, a workshop was held with the faculty champions and NEEF staff in which we identified major program benefits, as well as challenges and suggestions for the future. Trainee baseline knowledge of environmental triggers was low, but they reported robust improvement in environmental triggers knowledge and intention to recommend environmental management. The program has a broad, national scope, reaching more than 12 000 physicians, health care providers, and students, and some faculty champions successfully integrated materials into health record. Program barriers and future endeavors were identified.
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Affiliation(s)
| | - Nicholas Newman
- Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Leyla E. McCurdy
- National Environmental Education Foundation, Washington, DC, USA
| | - Jane S. Chang
- National Environmental Education Foundation, Washington, DC, USA
| | | | | | | | - Megan Sandel
- Boston University School of Medicine, Boston, MA, USA
| | - Lynnette Mazur
- University of Texas Health Sciences Center, Houston, TX, USA
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Abstract
Indoor environmental exposures, particularly allergens and pollutants, are major contributors to asthma morbidity in children; environmental control practices aimed at reducing these exposures are an integral component of asthma management. Some individually tailored environmental control practices that have been shown to reduce asthma symptoms and exacerbations are similar in efficacy and cost to controller medications. As a part of developing tailored strategies regarding environmental control measures, an environmental history can be obtained to evaluate the key indoor environmental exposures that are known to trigger asthma symptoms and exacerbations, including both indoor pollutants and allergens. An environmental history includes questions regarding the presence of pets or pests or evidence of pests in the home, as well as knowledge regarding whether the climatic characteristics in the community favor dust mites. In addition, the history focuses on sources of indoor air pollution, including the presence of smokers who live in the home or care for children and the use of gas stoves and appliances in the home. Serum allergen-specific immunoglobulin E antibody tests can be performed or the patient can be referred for allergy skin testing to identify indoor allergens that are most likely to be clinically relevant. Environmental control strategies are tailored to each potentially relevant indoor exposure and are based on knowledge of the sources and underlying characteristics of the exposure. Strategies include source removal, source control, and mitigation strategies, such as high-efficiency particulate air purifiers and allergen-proof mattress and pillow encasements, as well as education, which can be delivered by primary care pediatricians, allergists, pediatric pulmonologists, other health care workers, or community health workers trained in asthma environmental control and asthma education.
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Abrams EM, Szefler SJ, Becker AB. Effect of asthma therapies on the natural course of asthma. Ann Allergy Asthma Immunol 2016; 117:627-633. [PMID: 28073701 DOI: 10.1016/j.anai.2016.09.438] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 09/19/2016] [Accepted: 09/23/2016] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To provide an evidence-based review on the role of pharmacologic (inhaled corticosteroids, leukotriene receptor antagonists, biologic therapies, aeroallergen immunotherapy) and nonpharmacologic therapies (environmental modifications, microbiome) in secondary and tertiary asthma prevention. DATA SOURCES A PubMed search for English-language publications regarding asthma and secondary or tertiary prevention was performed. Some articles cited in selected studies were also considered for inclusion in this review. STUDY SELECTIONS Studies were included that were original research and specifically addressed the question of asthma prevention and use of pharmacologic or nonpharmacologic therapies. When possible, we selected the articles with the most robust level of evidence. RESULTS More than 100 articles were initially identified, 79 were reviewed in depth, and 60 were included in this review. Several studies suggest no disease-modifying effect for inhaled corticosteroids. Small studies suggest a tertiary preventive effect for leukotriene receptor antagonists. Biological therapies have somewhat conflicting evidence with a paucity of pediatric data, although some have tremendous promise. A role of allergen immunotherapy (specifically pollen) in secondary asthma prevention has been suggested, with no firm conclusions possible for tertiary prevention. One large trial suggests a role for environmental modifications in secondary asthma prevention, whereas the preponderance of evidence does not suggest a role in tertiary prevention. The microbiome is an active area of research that has promise for a disease-modifying effect. CONCLUSION Further work needs to be performed to allow physicians to intervene early and alter the natural course of asthma in children.
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Affiliation(s)
- Elissa M Abrams
- Department of Pediatrics, Section of Allergy and Clinical Immunology, University of Manitoba, Winnipeg, Manitoba, Canada.
| | - Stanley J Szefler
- Department of Pediatrics, Section of Pulmonology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, Colorado
| | - Allan B Becker
- Department of Pediatrics, Section of Allergy and Clinical Immunology, University of Manitoba, Winnipeg, Manitoba, Canada
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Badran HS, Hussein A, Salah M, Lotfi WT. Identification and Prevalence of Allergic, Nonallergic, and Local Allergic Rhinitis Patients in Western Area, Saudi Arabia. Ann Otol Rhinol Laryngol 2016; 125:634-43. [PMID: 27067153 DOI: 10.1177/0003489416642785] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To evaluate the diagnostic yield of skin prick test (SPT) and serum total immunoglobulin E (IgE) antibodies level in patients with allergic rhinitis (AR) and the role of nasal provocation test (NPT) for the determination of local allergic rhinitis (LAR) in patients with nonallergic rhinitis (NAR). METHODOLOGY This multi-center study included 1230 patients with clinical manifestations for ≥2 years. Patients were classified according to the Allergic Rhinitis and Its Impact on Asthma (ARIA) and scored according to the quantitative Score for Allergic Rhinitis (SFAR). The SPT and total IgE antibody levels were done for all patients. Patients gave negative SPT underwent NPT, and its result was interpreted using Lebel Symptom Score Scale. RESULTS The SPT was positive in 77.8% of patients, mostly for grass pollen and dust mites. All patients were sensitive to multiple allergens. Median serum IgE antibody level for total study population was 162 IU/ml. Forty-two patients (3.4%) with negative SPT showed a weak response to NPT, while 231 patients (18.7%) with negative SPT had a high response to NPT and were considered to have LAR. CONCLUSION The SPT could discriminate between AR and NAR patients. The NPT could identify LAR in 84.6% of patients with rhinitis among those considered as NAR.
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Affiliation(s)
- Hatem S Badran
- Department of Otorhinolaryngology, Faculty of Medicine, Cairo University, Egypt
| | - Ahmed Hussein
- Department of Otorhinolaryngology, Faculty of Medicine, Cairo University, Egypt
| | - Mohamad Salah
- Department of Otorhinolaryngology, Faculty of Medicine, Zagazig University, Egypt
| | - Wassim T Lotfi
- Department of Otorhinolaryngology, Faculty of Medicine, Fayoum University, Egypt
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Tsurikisawa N, Saito A, Oshikata C, Yasueda H, Akiyama K. Effective allergen avoidance for reducing exposure to house dust mite allergens and improving disease management in adult atopic asthmatics. J Asthma 2016; 53:843-53. [PMID: 27049597 DOI: 10.3109/02770903.2016.1155218] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE We investigated the best strategy for adult asthmatics to avoid exposure to Dermatophagoides group (Der-1) allergens. METHODS Adult atopic asthmatics (n = 111) followed a 32-item checklist for avoiding Der-1 allergen exposure. Twenty-five patients were excluded through incomplete sampling; 50 remaining patients encased their pillows/futons/mattresses in microfine-fiber covers, 13 used vacuum cleaners with dust-mite-collection nozzles, and 23 acted as non-intervention controls. During August-October 2010 and August-October 2011, dust samples were collected in Petri dishes placed in bedrooms for 2 weeks and from mattresses/futons by using adhesive tape on one morning. A Der-1 level decrease was defined as a mean 2011 Der-1 level of <1 as a ratio of the 2010 level on tape or Petri dish samples. We analyzed the associations between Der-1 level change (by ELISA) and % weekly variability in peak expiratory flow (PEF) or fraction of exhaled nitric oxide (FeNO) after intervention. RESULTS Der-1 levels decreased significantly in the covers group but not the vacuuming group. FeNO levels and PEF variability were unchanged in both groups. In patients whose Petri dish or tape samples showed decreased Der-1 levels, the % PEF variability was lower in 2011 than in 2010, but FeNO levels were unchanged. Three interventions (vacuuming all family members' mattress/futon surfaces at least weekly or after exposure of the futons to sunlight, and floor wiping before vacuuming), plus using covers, were the most effective management strategy in reducing Der-1 levels. CONCLUSIONS This environmental and bedding maintenance program may help manage adult atopic asthma.
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Affiliation(s)
- Naomi Tsurikisawa
- a Department of Allergy and Respirology , National Hospital Organization Sagamihara National Hospital , Kanagawa , Japan.,c Department of Respirology , National Hospital Organization Saitama Hospital , Saitama , Japan
| | - Akemi Saito
- b Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital , Kanagawa , Japan
| | - Chiyako Oshikata
- a Department of Allergy and Respirology , National Hospital Organization Sagamihara National Hospital , Kanagawa , Japan.,c Department of Respirology , National Hospital Organization Saitama Hospital , Saitama , Japan
| | - Hiroshi Yasueda
- b Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital , Kanagawa , Japan
| | - Kazuo Akiyama
- a Department of Allergy and Respirology , National Hospital Organization Sagamihara National Hospital , Kanagawa , Japan
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15
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van Boven FE. Effectiveness of mite-impermeable covers: a hypothesis-generating meta-analysis. Clin Exp Allergy 2015; 44:1473-83. [PMID: 25048696 DOI: 10.1111/cea.12376] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Asthma is a heterogeneous disease. The subject of mite allergen control has evolved into a debate dominated by a Cochrane review by Gøtzsche and Johansen (Cochrane Database of Systematic Reviews, 2008, Art. No: CD001187). A not well-discussed aspect of that study is the selection by those authors of a univariate meta-analysis including various interventions. This study extends the meta-analysis by Gøtzsche and Johansen and aims to generate hypotheses on the effectiveness of various bedding interventions, including the coverage of all bedding elements. Trials were selected based on environmental criteria. The interventions were classified according to the number of barriers used. Standardized mean differences yielded the mite load, three physiological outcomes and asthma symptom scores. The influence of covariates was examined with a mixed-effect model using the metafor package for meta-analysis in R. Twelve trials included 1187 observations. The interventions included one barrier or product (six trials), two barriers or partial control (four trials) and three barriers or integral control (two trials). The exposure data showed considerable heterogeneity (I(2) = 93%). The risk of bias significantly (P = 0.04) influenced the final load, the square root of the interaction between the baseline load and the type of intervention as well (95% CI: -0.66 to -0.07 μg/g; P = 0.02). Changes in load showed similar tendencies. Health outcomes showed moderate to considerable heterogeneity (physiological outcomes I(2) = 44-94%; symptom score I(2) = 93%). A meta-regression of bedding interventions indicates that integral control most significantly reduced mite load when the load was high at baseline. The number of trials was too small to allow an appropriate examination of health outcomes. Future studies are suggested to test the hypothesis that allergic patients benefit from integral control when the baseline mite load is high.
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Affiliation(s)
- F E van Boven
- Working Group on Allergen Avoidance, V&VN Lung Care Nurses, V&VN Dutch Nurses' Association, Utrecht, The Netherlands
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Abstract
PURPOSE OF REVIEW To review and interpret recent literature related to the role of environmental control in prevention and treatment of asthma. RECENT FINDINGS Environmental control has a clearly established role in the management of asthma, but its role as a primary prevention tool is not supported by recent clinical trials. Although some of the interventions tested in these trials reduced the risk of asthma, the interventions often included dietary modification and those trials intervening only on environmental exposures were largely negative. Environmental interventions that target multiple asthma triggers, such as a laminar airflow device and relocation to high altitude, continue to demonstrate efficacy in asthma. Several studies highlight the efficacy of portable HEPA purifiers in reduction of indoor particulate matter and improving asthma outcomes. Several recently published practice parameters provide evidence-based recommendations for environmental control practices targeting furry pet, rodent, and cockroach allergens. Emerging work highlights the potential impact of spatial-temporal aspects of exposure and the shape of the dose-response relationships on the indoor allergen exposure-asthma relationship. SUMMARY Environmental interventions likely have no effect on the risk of developing atopic disease, but multifaceted interventions are generally of benefit in the management of asthma, particularly in children.
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Tsurikisawa N, Saito A, Oshikata C, Nakazawa T, Yasueda H, Akiyama K. Encasing bedding in covers made of microfine fibers reduces exposure to house mite allergens and improves disease management in adult atopic asthmatics. Allergy Asthma Clin Immunol 2013; 9:44. [PMID: 24499343 PMCID: PMC3829998 DOI: 10.1186/1710-1492-9-44] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 11/01/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Studies of avoidance of exposure to group 1 allergens of the Dermatophagoides group (Der p 1) have not yielded consistent improvements in adult asthma through avoidance. We explored whether the use of pillow and bed covers and allergen-avoidance counseling resulted in Der 1-level reduction, as measured by enzyme-linked immunosorbent assay, and thus improved asthma symptoms in adult patients. METHODS Twenty-five adult patients with moderate or severe atopic asthma were randomized into intervention and control groups. Intervention patients slept on pillows and mattresses or futons encased in microfine-fiber covers and were counseled in allergen avoidance through bedroom cleaning. Control patients received neither special covers nor counseling. In the period August to October in 2009 (pre-intervention) and 2010 (post-intervention), dust samples were collected in open Petri dishes placed in bedrooms for 2 weeks and by rapid lifting of dust from bedding and skin using adhesive tape on the morning of 1 day of Petri dish placement. We examined the associations between changes in Der 1 level (as measured by enzyme-linked immunosorbent assay) and clinical symptom score, minimum % peak expiratory flow, and fraction of exhaled nitric oxide. RESULTS Der 1 allergen levels on the mattress/futon covers and near the floor of the bedrooms of intervention patients, but not controls, were lower in 2010 than in 2009. From 2009 to 2010, asthma symptom scores decreased significantly, and minimum % peak expiratory flow increased significantly, in intervention patients. The fall in Der p 1 concentration was correlated with a reduction in the fraction of exhaled nitric oxide. CONCLUSIONS Minimization of Der 1 allergen exposure by encasing pillows and mattresses or futons and receiving counseling on avoiding exposure to indoor allergens improved asthma control in adult patients.
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Affiliation(s)
- Naomi Tsurikisawa
- Department of Allergy and Respirology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku, Sagamihara, Kanagawa 252-0392, Japan.
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Herzog R, Cunningham-Rundles S. Pediatric asthma: natural history, assessment, and treatment. ACTA ACUST UNITED AC 2012; 78:645-60. [PMID: 21913196 DOI: 10.1002/msj.20285] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Wheezing and childhood asthma are not synonymous but rather comprise a heterogeneous group of conditions that have different outcomes over the course of childhood. Most infants who wheeze have a transient condition associated with diminished airway function at birth and have no increased risk of asthma later in life. However, children with persistent wheezing throughout childhood and frequent exacerbations represent the main challenge today. Studying the natural history of asthma is important for the understanding and accurate prediction of the clinical course of different phenotypes. To date, a great improvement has been achieved in reducing the frequency of asthma symptoms. However, neither decreased environmental exposure nor controller treatment, as recommended by the recent National Asthma Education And Prevention Program, can halt the progression of asthma in childhood or the development of persistent wheezing phenotype. This review focuses on the recent studies that led to the current understanding of asthma phenotypes in childhood and the recommended treatments.
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Affiliation(s)
- Ronit Herzog
- Department of Pediatrics, Division of Allergy, Immunology and Pulmonology, Weill Medical College of Cornell University, New York, NY, USA.
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19
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It's time to rethink mite allergen avoidance. J Allergy Clin Immunol 2011; 128:723-727.e6. [PMID: 21855978 DOI: 10.1016/j.jaci.2011.07.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 05/26/2011] [Accepted: 07/07/2011] [Indexed: 11/24/2022]
Abstract
The role of allergen exposure in the etiology of allergic sensitization and asthma is complex. Advice on strategies to avoid domestic allergens remains contentious because trials of interventions aimed to prevent asthma or reduce symptoms have often failed to demonstrate benefits. Asthma management guidelines differ widely in their recommendations, while Web-based information often claims benefits associated with products. In this rostrum we argue that although many factors have a role in both the etiology and the exacerbation of asthma, allergen exposure probably remains an important contributor to the manifestations of the disease. Currently, there is no evidence-based framework for effective domestic allergen avoidance interventions to reduce chronic aeroallergen exposure. The development of an effective approach to allergen avoidance requires a better understanding of (a) the physical nature of chronic aeroallergen exposure and methods for measuring and reducing this, (b) the interaction between allergen exposure and innate immune modulators at different disease stages, and (c) markers enabling the identification of individuals who would benefit from this. The strategic risk of overemphasizing other novel mechanisms and approaches to asthma management is that we will prematurely abandon and fail to improve an existing approach that could have a significant impact on the development, progression, and symptoms of the disease.
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Abstract
PURPOSE OF REVIEW Indoor pollutants and allergens cause asthma symptoms and exacerbations and influence the risk of developing asthma. We review recent studies regarding the effects of the indoor environment on childhood asthma. RECENT FINDINGS Exposure to some indoor allergens and second hand smoke are causally related to the development of asthma in children. Many recent studies have demonstrated an association between exposure to indoor pollutants and allergens and airways inflammation, asthma symptoms, and increased healthcare utilization among individuals with established asthma. Genetic polymorphisms conferring susceptibility to some indoor exposures have also been identified, and recent findings support the notion that environmental exposures may influence gene expression through epigenetic modification. Recent studies also support the efficacy of multifaceted environmental interventions in childhood asthma. SUMMARY Studies have provided significant evidence of the association between many indoor pollutants and allergens and asthma morbidity, and have also demonstrated the efficacy of multifaceted indoor environmental interventions in childhood asthma. There is also a growing body of evidence suggesting that some indoor pollutants and allergens may increase the risk of developing asthma. Future studies should examine mechanisms whereby environmental exposures may influence asthma pathogenesis and expand the current knowledge of susceptibility factors for indoor exposures.
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Segundo GRS, Sopelete MC, Terra SA, Pereira FL, Justino CM, Silva DADO, Taketomi EA. Diversity of allergen exposure: implications for the efficacy of environmental control. Braz J Otorhinolaryngol 2010; 75:311-6. [PMID: 19575122 PMCID: PMC9450745 DOI: 10.1016/s1808-8694(15)30796-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 04/14/2007] [Indexed: 11/25/2022] Open
Abstract
The prevalence of allergic diseases such as asthma, rhinitis, allergic conjunctivitis and atopic dermatitis has increased in the last decades. The relationship between allergen exposure, atopic sensitization and development of allergic diseases is widely described in the literature. Aim To evaluate measures for reducing allergen exposure as part of the treatment of allergic diseases. Methods An analysis was made of previous studies on allergen exposure done with a similar methodology in the central region of Brazil; the study included homes, hotels, cinemas, cars, taxis, buses and scholar transportation. Results High levels of Der p 1 and Der f 1 mite allergens were found in a large proportion of the sample in most of the environments included in those studies; there were higher levels of pet allergens in cars and school transportation vehicles. Conclusion The diversity of allergen exposure demonstrates the need for education about allergic diseases for patients and their families, as well as measures of reducing allergens in homes. This should be part of a global strategy of the management of allergic diseases, given that individuals live in society, not only in their houses.
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Gent JF, Belanger K, Triche EW, Bracken MB, Beckett WS, Leaderer BP. Association of pediatric asthma severity with exposure to common household dust allergens. ENVIRONMENTAL RESEARCH 2009; 109:768-74. [PMID: 19473655 PMCID: PMC2706291 DOI: 10.1016/j.envres.2009.04.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Revised: 04/13/2009] [Accepted: 04/20/2009] [Indexed: 05/04/2023]
Abstract
BACKGROUND Reducing exposure to household dust inhalant allergens has been proposed as one strategy to reduce asthma. OBJECTIVE To examine the dose-response relationships and health impact of five common household dust allergens on disease severity, quantified using both symptom frequency and medication use, in atopic and non-atopic asthmatic children. METHODS Asthmatic children (N=300) aged 4-12 years were followed for 1 year. Household dust samples from two indoor locations were analyzed for allergens including dust mite (Der p 1, Der f 1), cat (Fel d 1), dog (Can f 1), cockroach (Bla g 1). Daily symptoms and medication use were collected in monthly telephone interviews. Annual disease severity was examined in models including allergens, specific IgE sensitivity and adjusted for age, gender, atopy, ethnicity, and mother's education. RESULTS Der p 1 house dust mite allergen concentration of 2.0 microg/g or more from the main room and the child's bed was related to increased asthma severity independent of allergic status (respectively, OR 2.93, 95% CI 1.37, 6.30 for 2.0-10.0 microg/g and OR 2.55 95% CI 1.13, 5.73 for 10.0 microg/g). Higher pet allergen levels were associated with greater asthma severity, but only for those sensitized (cat OR 2.41 95% CI 1.19, 4.89; dog OR 2.06 95% CI 1.01, 4.22). CONCLUSION Higher levels of Der p 1 and pet allergens were associated with asthma severity, but Der p 1 remained an independent risk factor after accounting for pet allergens and regardless of Der p 1 specific IgE status.
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Affiliation(s)
- Janneane F Gent
- Yale Center for Perinatal, Pediatric and Environmental Epidemiology, Department of Epidemiology and Public Health, Yale University School of Medicine, One Church Street, 6th Floor, New Haven, CT 06510, USA.
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Segundo GRS, Sopelete MC, Terra SA, Pereira FL, Justino CM, Silva DADO, Taketomi EA. Diversidade da exposição alergênica: implicações na obtenção da eficácia do controle ambiental. ACTA ACUST UNITED AC 2009. [DOI: 10.1590/s0034-72992009000200025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As doenças alérgicas, como a asma, rinite, conjuntivite alérgica e a dermatite atópica têm apresentado um aumento na sua prevalência nas últimas décadas. A relação entre exposição alergênica, sensibilização atópica e desenvolvimento de doenças alérgicas são amplamente descrita na literatura. OBJETIVO: Discutir a dificuldade no controle ambiental da exposição alergênica como parte do tratamento das doenças alérgicas. MÉTODOS: Analisar trabalhos de exposição alergênica realizados com metodologia similar na região central do Brasil, incluindo casas, hotéis, cinemas, carros, táxis, ônibus e transporte escolar. RESULTADOS: Níveis elevados dos alérgenos do grupo 1 de Dermatophagoides pteronyssinus (Der p 1) e de D. farinae (Der f 1), capazes de causar sensibilização e exacerbação de sintomas foram encontrados na maioria dos ambientes estudados em uma larga proporção das amostras, enquanto os alérgenos de animais domésticos atingiram maiores níveis em carros e veículos de transporte escolar. CONCLUSÃO: A diversidade da exposição alergênica mostra a necessidade de uma compreensão da doença alérgica pelos pacientes e familiares, e que as medidas de controle do ambiente doméstico fazem parte de uma estratégia global do tratamento das doenças alérgicas, uma vez que os indivíduos vivem em uma sociedade e não isoladas no interior de seus domicílios.
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Abstract
Inner-city residents continue to suffer disproportionate asthma morbidity despite recent progress in reducing asthma morbidity and mortality in other strata of the United States population. Studies over the past decade indicate that the indoor environment is a strong contributor to poor asthma control and asthma-related health care use in inner-city populations. Certain indoor exposures are more common and occur in higher concentrations in inner-city communities than in suburban communities. Identification of "asthmagenic" indoor exposures has paved the way for the development of intervention strategies aimed at reducing asthma morbidity. This article reviews the growing body of evidence that certain indoor environmental exposures contribute to the burden of asthma in the inner city.
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Abstract
The major allergen in house dust comes from mites. We performed a systematic review of the randomized trials that had assessed the effects of reducing exposure to house dust mite antigens in the homes of people with mite-sensitive asthma, and had compared active interventions with placebo or no treatment. Fifty-four trials (3002 patients) were included. Thirty-six trials assessed physical methods (26 mattress covers), 10 chemical methods and eight a combination of chemical and physical methods. Despite the fact that many trials were of poor quality and would be expected to exaggerate the reported effect, we did not find an effect of the interventions. For the most frequently reported outcome, peak flow in the morning (1565 patients), the standardized mean difference was 0.00 (95% confidence interval (CI) -0.10 to 0.10). There were no statistically significant differences in number of patients improved (relative risk 1.01, 95% CI 0.80-1.27), asthma symptom scores (standardized mean difference -0.04, 95% CI -0.15 to 0.07) or in medication usage (standardized mean difference -0.06, 95% CI -0.18 to 0.07). Chemical and physical methods aimed at reducing exposure to house dust mite allergens cannot be recommended.
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Affiliation(s)
- P C Gøtzsche
- Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark
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26
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Abstract
EDITORIAL NOTE This 2011 review predates current reporting standards and methodological expectations for Cochrane Reviews. It should not be used for clinical decision‐making. BACKGROUND The major allergen in house dust comes from mites. Chemical, physical and combined methods of reducing mite allergen levels are intended to reduce asthma symptoms in people who are sensitive to house dust mites. OBJECTIVES To assess the effects of reducing exposure to house dust mite antigens in the homes of people with mite-sensitive asthma. SEARCH STRATEGY PubMed and The Cochrane Library (last searches Nov 2007), reference lists. SELECTION CRITERIA Randomised trials of mite control measures vs placebo or no treatment in people with asthma known to be sensitive to house dust mites. DATA COLLECTION AND ANALYSIS Two authors applied the trial inclusion criteria and evaluated the data. Trial authors were contacted to clarify information. MAIN RESULTS Fifty-four trials (3002 patients) were included. Thirty-six trials assessed physical methods (26 mattress encasings), 10 chemical methods, and 8 a combination of chemical and physical methods. Despite the fact that many trials were of poor quality and would be expected to exaggerate the reported effect, we did not find an effect of the interventions. For the most frequently reported outcome, peak flow in the morning (1565 patients), the standardised mean difference was 0.00 (95% confidence interval (CI) -0.10 to 0.10). There were no statistically significant differences either in number of patients improved (relative risk 1.01, 95% CI 0.80 to 1.27), asthma symptom scores (standardised mean difference -0.04, 95% CI -0.15 to 0.07), or in medication usage (standardised mean difference -0.06, 95% CI -0.18 to 0.07). AUTHORS' CONCLUSIONS Chemical and physical methods aimed at reducing exposure to house dust mite allergens cannot be recommended. It is doubtful whether further studies, similar to the ones in our review, are worthwhile. If other types of studies are considered, they should be methodologically rigorous and use other methods than those used so far, with careful monitoring of mite exposure and relevant clinical outcomes.
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Affiliation(s)
- P C Gøtzsche
- Rigshospitalet, Dept. 3343, Nordic Cochrane Centre. Blegdamsvej 9, Copenhagen Ø, Denmark, 2100.
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Thyne SM, Rising JP, Legion V, Love MB. The Yes We Can Urban Asthma Partnership: a medical/social model for childhood asthma management. J Asthma 2007; 43:667-73. [PMID: 17092847 DOI: 10.1080/02770900600925288] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Pediatric asthma programs have struggled to integrate children's medical and social needs. We developed and piloted an integrated team model for asthma care for low-income children through the Yes We Can Urban Asthma Partnership. Program evaluation demonstrated increases in prescribing controller medications (p <0.05), use of action plans (p<0.001), and the use of mattress covers (p<0.001); and decrease in asthma symptoms (p<0.01). Additional changes occurred within the local system of asthma care to support ongoing efforts to improve asthma management. We conclude that pediatric asthma programs can effectively target the social and medical needs of children in a sustainable manner.
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Affiliation(s)
- Shannon M Thyne
- Department of Pediatrics, University of California, San Francisco, California 94110, USA.
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Sharma HP, Hansel NN, Matsui E, Diette GB, Eggleston P, Breysse P. Indoor environmental influences on children's asthma. Pediatr Clin North Am 2007; 54:103-20, ix. [PMID: 17306686 DOI: 10.1016/j.pcl.2006.11.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The burden of asthma for children in the United States is substantial and has continued to rise for the past 2 decades. There is growing evidence that the indoor environment may play an important role in the pathogenesis of childhood asthma. This article first reviews the effects of indoor allergen exposure and sensitization on asthma incidence and morbidity, focusing on dust mite, cockroach, pet, and rodent allergens. It then addresses the effects of indoor air pollutants (ozone, particulate matter, nitrogen dioxide, environmental tobacco smoke, sulfur dioxide, and carbon monoxide) on asthma morbidity.
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Affiliation(s)
- Hemant P Sharma
- Division of Allergy and Immunology, Department of Pediatrics, Johns Hopkins University School of Medicine, 600 North Wolfe Street, CMSC 1102, Baltimore, MD 21287, USA
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Semic Jusufagic A, Simpson A, Woodcock A. Dust mite allergen avoidance as a preventive and therapeutic strategy. Curr Allergy Asthma Rep 2006; 6:521-6. [PMID: 17026879 DOI: 10.1007/s11882-006-0031-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Asthma is a global health problem with genetic and environmental components. Indoor allergens have a major impact on asthma, and exposure in sensitized subjects can compromise lung function. A reduction in allergen exposure would seem a logical facet to treatment. Methods for reducing mite allergen levels that are effective in the laboratory may not work in the home and may not result in a clinical benefit. Six ongoing studies are investigating the effects of environmental control on the primary prevention of asthma and allergies. Although the Isle of Wight and Canadian studies provide encouraging results at age 8 and 7 years, respectively, it will be some time before a definitive public health message emerges. For secondary prevention, there is little evidence to support the use of mite-proof encasings as a single intervention in adults. In children, however, single or multifaceted interventions appear to be of some benefit.
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Affiliation(s)
- Aida Semic Jusufagic
- Academic Division of Medicine and Surgery, 2nd Floor Education and Research Center, University of Mancester, Wythenshawe Hospital, Southmoor Road, Mancester M23 9LT, UK
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Causer S, Shorter C, Sercombe J. Effect of floorcovering construction on content and vertical distribution of house dust mite allergen, Der p I. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2006; 3:161-8; quiz D45. [PMID: 16531289 DOI: 10.1080/15459620600572068] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Domestic floorcoverings often contain appreciable quantities of particulate pollutants, such as house dust mite allergen, Der p I. Exposure to Der p I is a risk factor for the development of mite sensitization and asthma. We investigated whether carpet construction was related to the Der p I content in normal use, and its vertical distribution. We hoped to inform development of methods to remove such material. Along with one hard flooring surface, a range of carpets with differing pile conformations (loop vs. cut), pile heights, yarn twists, and pile densities were placed in houses for 13 months. The carpets were later sectioned to allow profiling of Der p I throughout the pile strata using monoclonal antibody, enzyme-linked immunosorbent assay. Not surprisingly, significantly lower amounts of Der p I were found on hard flooring than any of the carpets, which all contained similar amounts of mite allergen. For all carpets, the Der p I concentration per unit area was found to be inversely related to the distance from the carpet backing. We conclude that carpet construction is not a good predictor of Der p I content in the home. We also suggest that, as carpet construction likely influences ease of disturbance of material within the pile, methods to remove or denature particulate pollutants such as Der p I will be most effective if they are able to target the bulk of allergenic material, found toward the base of the pile.
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Affiliation(s)
- Simon Causer
- Canesis Network Ltd., Christchurch, New Zealand.
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31
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Koshak EA. Skin test reactivity to indoor allergens correlates with asthma severity in jeddah, saudi arabia. ALLERGY, ASTHMA, AND CLINICAL IMMUNOLOGY : OFFICIAL JOURNAL OF THE CANADIAN SOCIETY OF ALLERGY AND CLINICAL IMMUNOLOGY 2006; 2:11-9. [PMID: 20529215 PMCID: PMC3231646 DOI: 10.1186/1710-1492-2-1-11] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND There is increased emphasis on the role of indoor allergens in asthma. OBJECTIVE To examine the spectrum of skin test reactivity (sensitization) to indoor allergens and its correlation with asthma severity in Jeddah, Saudi Arabia. METHODS Asthmatic patients referred to the allergy clinic at King Abdulaziz University Hospital (KAUH) in Jeddah were studied. Measures of clinical severity were adopted from national and international asthma guidelines. The degree of sensitization was assessed by the wheal size (positive >/= 3 mm) from standard skin-prick tests for the following common indoor inhalant allergens: house dust mites (Dermatophagoides pteronyssinus [Dp] and Dermatophagoides farinae [Df]), cat, and cockroach. RESULTS Skin test results from 113 of 151 (74.8%) asthmatic patients were positive for one or more allergens. The patients' ages ranged between 9 and 63 years (mean, 30 +/- 13 years), and females constituted 65.5%. The predominant asthma severity level was moderate persistent (55.8%), followed by mild persistent (33.6%). The prevalences of sensitization to indoor allergens were as follows: Dp, 87% (3-25 mm [mean, 7 mm]); Df, 84% (3-20 mm [mean, 7 mm]); cat, 44% (3-15 mm [mean, 6 mm]); and cockroach, 33% (3-12 mm [mean, 4 mm]). Higher asthma severity levels were significantly correlated with the number of allergens with positive sensitization (R = 0.3, p < .001) and with the degree of sensitization to house dust mites (Dp [degrees of freedom {df} = 16, p < .001] and Df [df = 17, p < .01]) but not to cat (df = 10, p < .24) or cockroach (df = 8, p < .36). CONCLUSIONS Immunoglobulin E-mediated skin test reactivity to indoor allergens, particularly to house dust mites, was common in asthmatic patients from Jeddah at KAUH. Increased sensitization was associated with higher levels of asthma severity, which is compatible with the literature. This emphasizes the importance of identifying sensitization to relevant indoor allergens in the clinical evaluation of asthmatic persons.
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Affiliation(s)
- Emad A Koshak
- Associate Professor and Consultant in Internal Medicine, Allergy, Asthma, and Clinical Immunology, Department of Internal Medicine, Faculty of Medicine, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
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Simpson A, Custovic A. The role of allergen avoidance in the secondary prevention of atopic disorders. Curr Opin Allergy Clin Immunol 2005; 5:223-7. [PMID: 15864079 DOI: 10.1097/01.all.0000168785.51711.27] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW Allergen avoidance is recommended as part of the treatment programme of many patients with allergic diseases in Europe and the USA. However, clinical trials of allergen avoidance tend to be small and the findings inconsistent. Several larger studies have recently been published, making a review of the new literature timely. RECENT FINDINGS There have been two large double-blind, placebo-controlled studies on the use of encasings (mattress, pillow and duvet) as a single intervention in adults with asthma. In both studies, participants in the active and the control group showed an improvement in peak flow, but there was no difference between groups over a 12-month period. A further smaller study of encasings reported an improvement in peak flow from 1 week in the active group; this study, however, was only of 9 weeks' duration. In children, the use of encasings was associated with a reduction in asthma medication usage, but not until 6 months into the study. A multifaceted intervention study, with the intervention tailored to the child's sensitization status and home environment (including environmental tobacco smoke), resulted in significant reductions in emergency room visits and symptoms in the active group. SUMMARY The evidence suggests that interventions in children (either single or multifaceted) are associated with a meaningful and sustained improvement in asthma control. However, for adults, allergen proof encasings as a single intervention cannot be recommended. There is a need for a large-scale multifaceted intervention study in adults with asthma.
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Affiliation(s)
- Angela Simpson
- North West Lung Centre, Wythenshawe Hospital, Manchester, UK.
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Kobayashi Y, Sakuma K, Hosoi J, Suda Y, Maeno K, Miyazawa K, Ichikawa H, Kohno Y. Reduction of Cedar Pollen Adhesion by Lecithin Polymer Coating. Allergol Int 2005. [DOI: 10.2332/allergolint.54.573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Horak F, Matthews S, Ihorst G, Arshad SH, Frischer T, Kuehr J, Schwieger A, Forster J. Effect of mite-impermeable mattress encasings and an educational package on the development of allergies in a multinational randomized, controlled birth-cohort study -- 24 months results of the Study of Prevention of Allergy in Children in Europe. Clin Exp Allergy 2004; 34:1220-5. [PMID: 15298561 DOI: 10.1111/j.1365-2222.2004.02024.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Sensitization to house dust mite (HDM) is an important risk factor for the development of asthma and allergic disease in childhood. Higher levels of HDM allergen are linked to increased sensitization to HDM. OBJECTIVE To study the effect of mite-impermeable mattress encasings and an educational package on the development of allergies in a newborn cohort. METHODS Six hundred and ninety-six newborns at high risk of developing allergies were enrolled in three European countries (Germany, Austria, UK) in a prospective, randomized, controlled birth-cohort study. Children were randomly assigned to an intervention and control group. Intervention measures included the use of mite-impermeable mattress encasings for the child's bed and a simple educational package on allergen avoidance. The control group received basic information about allergies. Children were followed up at age 6, 12, 18 and 24 months. RESULTS 80.9% of the children were followed up to the age of 24 months. No difference in the prevalence of sensitization to HDM (control vs. intervention group: 8.4% vs. 6.1%, P=0.33) or the development of symptoms (recurrent wheezing 10.3% vs. 10.7%, nocturnal cough 12.5% vs. 12.5%) or allergic diseases (asthma 3.5% vs. 5.1%, eczema 20.0% vs. 19.6%, rhinitis 28.9% vs. 25.8%) could be found between the control and intervention group. CONCLUSION In this study, HDM avoidance did not show a protective effect on the development of sensitization to HDM or symptomatic allergy in children at age 24 months.
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Affiliation(s)
- F Horak
- University Children's Hospital, Vienna, Austria
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Abstract
BACKGROUND The major allergen in house dust comes from mites. Chemical, physical and combined methods of reducing mite allergen levels are intended to reduce asthma symptoms in people who are sensitive to house dust mites. OBJECTIVES To assess the effects of reducing exposure to house dust mite antigens in the homes of people with mite-sensitive asthma. SEARCH STRATEGY Cochrane Airways Group trials register, and PubMed and The Cochrane Library (last searches June 2004), reference lists. SELECTION CRITERIA Randomised trials of mite control measures vs placebo or no treatment in asthmatic people known to be sensitive to house dust mites. DATA COLLECTION AND ANALYSIS Two reviewers applied the trial inclusion criteria, assessed their quality and extracted the data independently. Study authors were contacted to clarify information. MAIN RESULTS Forty-nine trials (2733 patients) were included; the number of patients has more than doubled since the last version of this review. Thirty-one trials assessed physical methods, ten assessed chemical methods, and eight a combination of chemical and physical methods. Despite the fact that many trials were of poor quality and would be expected to exaggerate the reported effect, we did not find an effect of the interventions. For the most frequently reported outcome, peak flow in the morning (1339 patients), the standardised mean difference was -0.02 (95% confidence interval (CI) -0.13 to 0.08). There were no statistically significant differences either in number of patients improved (relative risk 1.01, 95% CI 0.80 to 1.27), asthma symptom scores (standardised mean difference -0.01, 95% CI -0.10 to 0.13), or in medication usage (standardised mean difference -0.05, 95% CI -0.18 to 0.09). REVIEWERS' CONCLUSIONS Chemical and physical methods aimed at reducing exposure to house dust mite allergens cannot be recommended. It is doubtful whether further studies, similar to the ones in our meta-analysis, are worthwhile. If other types of studies are considered, they should be methodologically rigorous and use other methods than those used so far, with careful monitoring of mite exposure and relevant clinical outcomes.
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Affiliation(s)
- P C Gøtzsche
- Nordic Cochrane Centre, Rigshospitalet, Dept. 7112, Blegdamsvej 9, Copenhagen Ø, Denmark, 2100
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Morgan WJ, Crain EF, Gruchalla RS, O'Connor GT, Kattan M, Evans R, Stout J, Malindzak G, Smartt E, Plaut M, Walter M, Vaughn B, Mitchell H. Results of a home-based environmental intervention among urban children with asthma. N Engl J Med 2004; 351:1068-80. [PMID: 15356304 DOI: 10.1056/nejmoa032097] [Citation(s) in RCA: 720] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Children with asthma who live in the inner city are exposed to multiple indoor allergens and environmental tobacco smoke in their homes. Reductions in these triggers of asthma have been difficult to achieve and have seldom been associated with decreased morbidity from asthma. The objective of this study was to determine whether an environmental intervention tailored to each child's allergic sensitization and environmental risk factors could improve asthma-related outcomes. METHODS We enrolled 937 children with atopic asthma (age, 5 to 11 years) in seven major U.S. cities in a randomized, controlled trial of an environmental intervention that lasted one year (intervention year) and included education and remediation for exposure to both allergens and environmental tobacco smoke. Home environmental exposures were assessed every six months, and asthma-related complications were assessed every two months during the intervention and for one year after the intervention. RESULTS For every 2-week period, the intervention group had fewer days with symptoms than did the control group both during the intervention year (3.39 vs. 4.20 days, P<0.001) and the year afterward (2.62 vs. 3.21 days, P<0.001), as well as greater declines in the levels of allergens at home, such as Dermatophagoides farinae (Der f1) allergen in the bed (P<0.001) and on the bedroom floor (P=0.004), D. pteronyssinus in the bed (P=0.007), and cockroach allergen on the bedroom floor (P<0.001). Reductions in the levels of cockroach allergen and dust-mite allergen (Der f1) on the bedroom floor were significantly correlated with reduced complications of asthma (P<0.001). CONCLUSIONS Among inner-city children with atopic asthma, an individualized, home-based, comprehensive environmental intervention decreases exposure to indoor allergens, including cockroach and dust-mite allergens, resulting in reduced asthma-associated morbidity.
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Affiliation(s)
- Wayne J Morgan
- Arizona Respiratory Center, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA
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Duran-Tauleria E, Vignati G, Guedan MJA, Petersson CJ. The utility of specific immunoglobulin E measurements in primary care. Allergy 2004; 59 Suppl 78:35-41. [PMID: 15245356 DOI: 10.1111/j.1398-9995.2004.00566.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The identification of atopic patients may not be considered a necessary step in the diagnosis process in primary care. This study investigated the impact of the addition of a specific immunoglobulin E (IgE) antibody test on the current management by primary-care physicians of patients with respiratory and skin symptoms. METHODS The study had a prospective before-after design. It was conducted in two geographic areas of Italy and Spain and consisted of two parts, Part I and Part II. In each part patients were recruited according to inclusion and exclusion criteria. After the clinical examination, the patients were classified into one of the following categories using a physician's classification: allergic, nonallergic or uncertain. A blood sample was taken from each included patient for specific IgE antibody determination using a Pharmacia CAP System, including either Phadiatop Infant (0-5 years of age) or Phadiatop and food mix (fx5e) (>5 years of age). If a positive result was found, an additional 6-26 specific IgE tests were performed. In Part I the result of the specific IgE antibody determinations was not available before the physician's classification was made. In contrast, in Part II, the result of the IgE test was available at the time when the physician's classification was made. Between Part I and Part II an educational intervention for physicians to improve their knowledge of blood testing for IgE-mediated allergy was carried out. RESULTS A total of 721 patients were included in the study. The agreement between classifications based on clinical data and IgE antibody results changed from a kappa coefficient of 0.13 in Part I to 0.86 in Part II. With regard to the allergic status the proportion of uncertain cases was reduced from 26.3% in Part I to 4.1% in Part II. The proportion of patients that were advised to avoid allergens increased from 18% in Part I to 62% in Part II in the group of patients classified both by the clinician and the IgE test. CONCLUSIONS The use of specific IgE antibody determinations improves the clinical management of patients with allergy related symptoms in primary care, allowing advice to be given on specific allergen avoidance. However, the applicability of this diagnostic tool in different areas and countries should be further assessed in cost-effectiveness studies.
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Karlsson AS, Renström A, Hedrén M, Larsson K. Allergen avoidance does not alter airborne cat allergen levels in classrooms. Allergy 2004; 59:661-7. [PMID: 15147452 DOI: 10.1111/j.1398-9995.2004.00519.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Some schools in Sweden offer allergen avoidance classrooms for allergic children with severe asthma. However, the measures commonly used to achieve a reduction in allergen levels have not been properly evaluated. The aim of the present prospective study was to study whether the levels of airborne cat allergen are altered after introducing feasible intervention measures in classrooms, without interfering with peoples' freedom of choice regarding pet ownership. METHODS Twenty-five classes, including five established allergy prevention classrooms participated in the study during a school year. After one term, six classes underwent a number of intervention measures recommended by the Swedish National Institute of Public Health. Curtains, upholstery and plants were removed, bookshelves were replaced with cupboards and regular cleaning was increased. Airborne dust was collected weekly (32 weeks) using duplicate Petri dishes (n = 1574) and on six occasions using two personal air samplers in each class (n = 264). RESULTS Airborne cat allergen levels were showing a similar variability throughout the whole study in all classes. Despite extensive measures in order to reduce allergen exposure, cat allergen levels were unaltered in the six classes after intervention. Allergen levels were not significantly lower in the established allergy prevention classes, compared with the other classes. Cat allergen levels differed, however, significantly between classes with few and many cat owners (P < 0.05). CONCLUSIONS We conclude that the recommended allergen avoidance measures used in this study did not reduce airborne cat allergen. It seems plausible that measures that fail to reduce allergen levels also fail to influence health status in allergic children but this remains to be shown.
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Affiliation(s)
- A-S Karlsson
- Lung and Allergy Research, National Institute of Environmental Medicine, Karolinska Institutet, Box 287, S-171 77 Stockholm, Sweden
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Recer GM. A review of the effects of impermeable bedding encasements on dust-mite allergen exposure and bronchial hyper-responsiveness in dust-mite-sensitized patients. Clin Exp Allergy 2004; 34:268-75. [PMID: 14987307 DOI: 10.1111/j.1365-2222.2004.01863.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Sensitization and exposure to dust-mite antigens are causative factors in the development and exacerbation of asthma. Impermeable bedding encasements are considered a first-line treatment to reduce dust-mite antigen exposure in clinical asthma-management guidelines. Public-health recommendations for environmental asthma treatments should be based on the weight of evidence supporting the reliability of environmental interventions so that uncertainties regarding their effectiveness can be accurately communicated to patients, and so that limited public-health resources can be most effectively utilized. OBJECTIVE To evaluate the strength of a clinical-trial evidence supporting the efficacy of bedding encasements as an asthma treatment. METHODS A narrative review was conducted of all clinical trials involving bedding encasement for the treatment of asthma. Collective statistical analyses were also performed to characterize the quantitative effect of bedding encasement on dust-mite allergen exposure and bronchial hyper-responsiveness (BHR) when used by asthma patients. RESULTS Over 30 clinical trials were reviewed. Of those studies reporting adequate exposure and BHR results, four reported significant reduction in dust-mite allergen exposure and concomitant BHR reduction in active-treatment groups using bedding encasements. In 10 studies, mite-allergen exposure was reportedly decreased during the study, but BHR was not changed in the active-treatment group or was reduced to a similar degree in the active-treatment and control groups. Five other studies reported a lack of significant effect of the intervention on exposure and BHR. Collective paired analyses found that the effect of bedding encasement on allergen exposure and BHR tended toward only a modest, non-significant improvement. Collectively, effects of bedding encasement on BHR and dust-mite allergen exposure were modestly correlated only when the baseline exposure was above 2 microg Type 1 antigen per gram settled dust. CONCLUSION Although bedding encasement might be an effective asthma treatment under some conditions, when implemented in clinical trials by asthma patients, its effectiveness is inconsistent and appears to be, at best, modest. Therefore, its significance as a reliable asthma management modality for any individual asthma patient is uncertain. Where resource constraints are significant, targeting the use of variably effective interventions such as bedding encasements toward those patient sub-populations most likely to derive substantial benefit may gain the largest net public-health benefit.
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Affiliation(s)
- G M Recer
- New York State Department of Health, Center for Environmental Health, Troy, NY 12180, USA.
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Does encasing bedding to exclude house dust mites benefit patients with rhinitis? Curr Allergy Asthma Rep 2004. [DOI: 10.1007/s11882-004-0053-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Luczynska C, Tredwell E, Smeeton N, Burney P. A randomized controlled trial of mite allergen-impermeable bed covers in adult mite-sensitized asthmatics. Clin Exp Allergy 2004; 33:1648-53. [PMID: 14656350 DOI: 10.1111/j.1365-2222.2003.01729.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mite-allergic patients with allergic disease should benefit from avoiding mite allergens. Many physicians, however, are yet to be convinced that allergen avoidance can make a significant contribution to asthma management in these patients. Many allergen-avoidance regimes include multiple measures of allergen reduction, but as mite exposure in the home is most likely to be greatest in bed dust, bedding is usually the first target for intervention. OBJECTIVE This study selected adult patients considered to be most likely to benefit from avoiding mite allergens, namely diagnosed asthmatics, sensitized to house dust mites and exposed to mite allergen in their mattresses. Patients were randomized into a placebo-controlled trial of the use of allergen-impermeable bed covers for 12 months, without any other form of mite-reduction measures. METHODS Adults with asthma were selected from general practices and asthma clinics in south-east London. Their serum IgE to mite allergens and allergen content of mattress dust samples were measured. Those with >0.70 kU/L mite-specific IgE and >2 microg/g Der p 1 were randomized into active or placebo treatments. Information was collected on allergic symptoms and medication use and quarterly peak flow diaries were kept throughout the trial. Dog or cat allergic patients were excluded if they had a pet at home to which they were sensitized. RESULTS The mean decrease in microg/g Der p 1 was 25.7 (95% CI 8.9, 74.1) in the active group and 4.5 (95% CI 1.8, 11.5) in the placebo group. Der p 1 concentrations in the active and placebo groups at the end of the trial were not significantly different. There was no effect on peak flow or asthma symptoms in a simple comparison of the treatment and placebo groups. CONCLUSION In this group of patients, mite allergen avoidance in the bed by the use of allergen-impermeable bedding alone cannot be recommended as an effective way of relieving asthma symptoms.
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Affiliation(s)
- C Luczynska
- Department of Public Health Sciences, King's College London, UK.
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Eggleston PA. Control of environmental allergens as a therapeutic approach. Immunol Allergy Clin North Am 2004; 23:533-47, viii-ix. [PMID: 14524390 DOI: 10.1016/s0889-8561(03)00003-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The first rule of environmental allergen control is that avoidance is appropriate for allergic patients with asthma. Although this rule is obvious to allergists, it frequently is not considered by families and physicians who are not trained in allergy. The next step in environmental avoidance is to determine the specific sensitivity of a patient. Clinically, practitioners have to address reduction of exposure to more than one allergen, and it is likely that the complexity of dealing with several treatment regimes decreases compliance.
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Affiliation(s)
- Peyton A Eggleston
- Department of Pediatrics, Johns Hopkins University, Johns Hopkins Hospital, 600 North Wolfe Street, CMSC 1102, Baltimore, MD 21287, USA.
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Takaro TK, Krieger JW, Song L. Effect of environmental interventions to reduce exposure to asthma triggers in homes of low-income children in Seattle. JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY 2004; 14 Suppl 1:S133-43. [PMID: 15118754 DOI: 10.1038/sj.jea.7500367] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The effectiveness of community health workers (CHWs) assisting families in reducing exposure to indoor asthma triggers has not been studied. In all, 274 low-income asthmatic children were randomly assigned to high- or low-intensity groups. CHWs visited all homes to assess exposures, develop action plans and provide bedding encasements. The higher-intensity group also received cleaning equipment and five to nine visits over a year focusing on asthma trigger reduction. The asthma trigger composite score decreased from 1.56 to 1.19 (Delta=-0.37, 95% CI 0.13, 0.61) in the higher-intensity group and from 1.63 to 1.43 in the low-intensity group (Delta=-0.20, 95% CI 0.004, 0.4). The difference in this measure due to the intervention was significant at the P=0.096 level. The higher-intensity group also showed improvement during the intervention year in measurements of condensation, roaches, moisture, cleaning behavior, dust weight, dust mite antigen, and total antigens above a cut point, effects not demonstrated in the low-intensity group. CHWs are effective in reducing asthma trigger exposure in low-income children. Further research is needed to determine the effectiveness of specific interventions and structural improvements on asthma trigger exposure and health.
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Affiliation(s)
- Tim K Takaro
- Occupational and Environmental Medicine, University of Washington School of Public Health and Community Medicine, Seattle, WA 98105, USA.
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Woodcock A, Forster L, Matthews E, Martin J, Letley L, Vickers M, Britton J, Strachan D, Howarth P, Altmann D, Frost C, Custovic A. Control of exposure to mite allergen and allergen-impermeable bed covers for adults with asthma. N Engl J Med 2003; 349:225-36. [PMID: 12867606 DOI: 10.1056/nejmoa023175] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The effectiveness of avoidance of house-dust-mite allergen (Dermatophagoides pteronyssinus 1 [Der p1]) in the management of asthma is uncertain. METHODS We conducted a double-blind, randomized, placebo-controlled study of allergen-impermeable bed covers involving 1122 adults with asthma. The primary outcomes were the mean morning peak expiratory flow rate over a four-week period during the run-in phase and at six months and the proportion of patients who discontinued inhaled corticosteroid therapy as part of a phased-reduction program during months 7 through 12. Der p1 was measured in mattress dust in a 10 percent random subsample of homes at entry and at 6 and 12 months. RESULTS The prevalence of sensitivity to dust-mite allergen was 65.4 percent in the group supplied with allergen-impermeable bed covers (active-intervention group) and 65.1 percent in the control group supplied with non-impermeable bed covers. The concentration of Der p1 in mattress dust was significantly lower in the active-intervention group at 6 months (geometric mean, 0.58 microg per gram vs. 1.71 microg per gram in the control group; P=0.01) but not at 12 months (1.05 microg per gram vs. 1.64 microg per gram; P=0.74). The mean morning peak expiratory flow rate improved significantly in both groups (from 410.7 to 419.1 liters per minute in the active-intervention group, P<0.001 for the change; and from 417.8 to 427.4 liters per minute in the control group, P<0.001 for the change). After adjustment for base-line differences (by analysis of covariance), there was no significant difference between the groups in the peak expiratory flow rate at six months (difference in means, active-intervention group vs. control group, -1.6 liters per minute [95 percent confidence interval, -5.9 to 2.7] among all patients [P=0.46] and -1.5 liters per minute [95 percent confidence interval, -6.9 to 3.9] among mite-sensitive patients [P=0.59]). There was no significant difference between the groups in the proportion in whom complete cessation of inhaled corticosteroid therapy was achieved (17.4 percent in the active-intervention group and 17.1 percent in the control group) or in the mean reduction in steroid dose, either among all patients or among mite-sensitive patients. CONCLUSIONS Allergen-impermeable covers, as a single intervention for the avoidance of exposure to dust-mite allergen, seem clinically ineffective in adults with asthma.
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Affiliation(s)
- Ashley Woodcock
- South Manchester Academic Group, University of Manchester, North West Lung Centre, Wythenshawe Hospital, Manchester, United Kingdom.
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Høst A, Andrae S, Charkin S, Diaz-Vázquez C, Dreborg S, Eigenmann PA, Friedrichs F, Grinsted P, Lack G, Meylan G, Miglioranzi P, Muraro A, Nieto A, Niggemann B, Pascual C, Pouech MG, Rancé F, Rietschel E, Wickman M. Allergy testing in children: why, who, when and how? Allergy 2003; 58:559-69. [PMID: 12823111 DOI: 10.1034/j.1398-9995.2003.00238.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Arlian LG, Vyszenski-Moher DL, Morgan MS. Mite and mite allergen removal during machine washing of laundry. J Allergy Clin Immunol 2003; 111:1269-73. [PMID: 12789228 DOI: 10.1067/mai.2003.1547] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Few studies have investigated live house dust mite and mite allergen removal from clothing and bedding by washing machines. No studies have investigated the transfer of mites from infested to uninfested clothing and bedding during washing. OBJECTIVE The purpose of this study was to wash different types of clothing and bedding in residential washing machines to determine the live Dermatophagoides farinae mite and allergen removal and the mite transfer from mite-infested items to mite-free items. METHODS Clothing and bedding items were machine washed in 6- and 8-lb loads in warm (36 degrees C-38 degrees C) or cold (22 degrees C-27 degrees C) water with and without recommended concentrations of laundry detergent and sodium hypochlorite bleach. Live mites and allergen present in washed versus unwashed and washed mite-infested versus washed mite-free items were compared. RESULTS Washing clothing and bedding in water alone, detergent, or detergent plus bleach removed 60% to 83% of the live mites. Washing removed more mites from some items than from others. When mite-infested items were washed with identical sets of mite-free items, many live mites were transferred to the previously mite-free items. Overall, 84% of Der f 1 was removed from items washed in water alone or in detergent and 98% from items washed in detergent plus bleach. CONCLUSIONS Washing clothing and bedding in cold or warm water with detergent or detergent plus bleach removed most allergen and a significant (P <.05) portion of live mites. Repeated washing is required to further reduce mite levels. Live mites were transferred from mite-infested to mite-free items during washing.
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Affiliation(s)
- Larry G Arlian
- Department of Biological Sciences, Wright State University, Dayton, OH 45435-0001, USA
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Boner A, Pescollderungg L, Silverman M. The role of house dust mite elimination in the management of childhood asthma: an unresolved issue. Allergy 2003; 57 Suppl 74:23-31. [PMID: 12371910 DOI: 10.1034/j.1398-9995.57.s74.5.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Indoor allergens are likely to be direct environmental causes of asthma and mite exposure, and sensitization is the most important environmental risk factor for childhood asthma in temperate zones. Analagous to occupational asthma, allergen avoidance in asthmatic children sensitized and exposed to mite allergens is associated with a reduction in airway hyperresponsiveness and symptoms associated with improvement in lung function. The long-term effect of this strategy needs to be prospectively evaluated considering both the timing and duration of exposure, as well as the timing and duration of removal. In order to be successful, it is important to achieve and maintain a major reduction on allergen levels, for a long period of time.
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Affiliation(s)
- A Boner
- Department of Pediatrics, University of Verona, Italy
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Abstract
Symptom persistence in difficult asthmatics may be related to their home environment. If sensitised asthmatics are to benefit from indoor allergen avoidance measures, these must be rigorous and drug adherence satisfactory. This is difficult for many families. The relationship between traffic pollution, asthma diagnosis and symptom severity is persuasive but requires objective validation. Overall, it seems that house dust mite control and tobacco smoke avoidance are important for asthmatics and advice about how to avoid these adverse factors must be given. Whether these measures are effective in difficult asthmatics and whether moving house makes any difference is unknown.
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Affiliation(s)
- Sejal Saglani
- Respiratory Paediatrics, Great Ormond Street Hospital, London WC1N 3JH, UK
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