1
|
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: 11] [Impact Index Per Article: 11.0] [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.
Collapse
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
| |
Collapse
|
2
|
Roberts G, Almqvist C, Boyle R, Crane J, Hogan SP, Marsland B, Saglani S, Woodfolk JA. Developments in the field of clinical allergy in 2018 through the eyes of Clinical and Experimental Allergy, Part II. Clin Exp Allergy 2020; 49:1550-1557. [PMID: 31833123 DOI: 10.1111/cea.13535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In this article, we describe developments in the field of clinical allergy as described by Clinical and Experimental Allergy in 2018; epidemiology, asthma and rhinitis, clinical allergy and allergens are all covered.
Collapse
Affiliation(s)
- Graham Roberts
- Clinical and Experimental Sciences and Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK.,NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.,The David Hide Asthma and Allergy Research Centre, St Mary's Hospital, Isle of Wight, UK
| | - C Almqvist
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Pediatric Allergy and Pulmonology Unit at Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - R Boyle
- Department of Paediatrics, Imperial College London, London, UK
| | - J Crane
- Department of Medicine, University of Otago Wellington, Wellington, New Zealand
| | - S P Hogan
- Department of Pathology, Mary H Weiser Food Allergy Center, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
| | - B Marsland
- Department of Immunology and Pathology, Monash University, Melbourne, Vic., Australia
| | - S Saglani
- National Heart & Lung Institute, Imperial College London, London, UK
| | - J A Woodfolk
- Division of Asthma, Allergy and Immunology, Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA, USA
| |
Collapse
|
3
|
van Boven FE, de Jong NW, Braunstahl GJ, Arends LR, Gerth van Wijk R. Effectiveness of the Air Purification Strategies for the Treatment of Allergic Asthma: A Meta-Analysis. Int Arch Allergy Immunol 2020; 181:395-402. [PMID: 32187604 DOI: 10.1159/000506284] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/27/2020] [Indexed: 12/26/2022] Open
Abstract
We updated the meta-analysis published by McDonald et al. [Chest 2002;122;1535-1542] by reviewing the effectiveness of air purification for the treatment of home-related allergic asthma (dust mite, dog, cat, and cockroach). We analysed the trials included by McDonald et al. as well as studies published since 2000. Data on asthma symptoms scores (ASS), medication use, forced expiratory volume in 1 s as a percentage of the predicted value (FEV1 %pred), histamine provocative concentration causing a 20% reduction in FEV1 (PC20), Asthma Quality of Life Questionnaire (AQLQ) scores, and fractional exhaled nitric oxide (FeNO) levels were extracted. The effectiveness was examined using metafor (registered in Prospero CRD42019127227). Ten trials including a total of 482 patients (baseline characteristics: mean FEV1 %pred 83.2%, I2 = 96.7%; mean PC20 4.93 mg/mL, I2 = 44.0%; mean AQLQ 4.67 [max. 7], I2 = 93.7%; mean FeNO 36.5 ppb, I2 = 0%) were included. We assessed the mean differences in the AQLQ scores as +0.36 (95% CI 0.10 to 0.62, p = 0.01, n = 302, I2 = 0%) and the FeNO levels as -6.67 ppb (95% CI -10.56 to -2.77, p = 0.0008, n = 304, I2 = 0%). The standardised mean differences in all other health outcomes were not significant (ASS -0.68, p = 0.20; medication use: -0.01, p = 0.94; FEV1 %pred -0.11, p = 0.34; PC20 +0.24, p = 0.53). We found statistically significant mean differences in the AQLQ scores and FeNO levels in patients with predominantly mild to moderate asthma at baseline. A large trial reported great improvement in the subgroup of patients receiving Global Initiative for Asthma step 4 therapy. We recommend that future studies on air purification focus on patients with severe and poorly controlled allergic asthma.
Collapse
Affiliation(s)
- Frank E van Boven
- Department of Internal Medicine, Section of Allergology and Clinical Immunology, Erasmus Medical Center, Rotterdam, The Netherlands,
| | - Nicolette W de Jong
- Department of Internal Medicine, Section of Allergology and Clinical Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Gert Jan Braunstahl
- Department of Pulmonology, Franciscus Gasthuis and Vlietland, Rotterdam, The Netherlands.,Department of Pulmonology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Lidia R Arends
- Department of Biostatistics, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Psychology, Education and Child Studies, Erasmus University Rotterdam, Rotterdam, The Netherlands
| | - Roy Gerth van Wijk
- Department of Internal Medicine, Section of Allergology and Clinical Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| |
Collapse
|
4
|
Custovic A, Murray CS, Simpson A. Dust-mite inducing asthma: what advice can be given to patients? Expert Rev Respir Med 2019; 13:929-936. [PMID: 31369320 DOI: 10.1080/17476348.2019.1651647] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Introduction: Amongst allergic asthmatics, high allergen exposure increases asthma severity. However, there is no consensus on the role of mite allergen avoidance in the management of asthma, and various guidelines differ in their recommendations. Areas covered: Several systematic reviews/meta-analyses on mite avoidance in the management of asthma have been published, and their findings have been used for a call to provide a recommendation in British guidelines that dust-mite control measures should not be recommended. However, there are several problems with such analysis (such as combining studies in adults and children), and we question whether these are appropriate tools to evaluate available evidence about mite allergen avoidance, and whether it is correct to rely disproportionately on the results of meta-analyses/systematic reviews to inform clinical practice in this area. Recent evidence in children suggests that mite-impermeable bed encasings reduce emergency hospital attendance with severe asthma exacerbations. Expert opinion: The practical questions include how to achieve a sufficient real-life reduction allergen exposure, and how to identify patients who will benefit from effective intervention. The intervention should start early in the natural history of asthma, and consideration for choosing patients should include using the titre of allergen-specific IgE antibodies or the size of skin test wheal as an indicator.
Collapse
Affiliation(s)
- Adnan Custovic
- National Heart and Lund Institute, Imperial College London , London , UK
| | - Clare S Murray
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre , Manchester , UK
| | - Angela Simpson
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre , Manchester , UK
| |
Collapse
|