The role of environmental allergen control in the management of asthma

Incorporating Aeroallergen Exposure Metrics into Clinical Asthma Care: A Pilot Study Using A Mixed-Methods Survey to Assess Aeroallergen Knowledge, Perceived Asthma Control, and Mitigation Strategies in Households of Children with Asthma

Objective: Mitigation of household allergens is associated with the reduction of asthma exacerbations in those with allergic asthma and is recommended in recent asthma guidelines. However, we need to better understand patient knowledge of aeroallergens in their homes prior to integrating direct allergen measurement methods into standard asthma care. Methods: We conducted a mixed-methods sequential pilot study consisting of a survey and virtual interview with caregivers of children aged 3 to 15 with asthma diagnosis (any severity) about asthma control, household environment, mitigation knowledge and strategies, and knowledge of allergens and asthma. Results: A total of 21 participants responded and 13 completed the virtual interview. Less than half identified mice (43%), rats (29%), and cockroaches (43%) as sources of allergens on the online survey, and no individuals mentioned these in discussions. Only 23% were able to define the term "allergen," but 69% could list examples. There was a poor correlation between perceived asthma control (57% stated asthma control was good or excellent) compared to asthma that was classified as well controlled per Expert Panel Report 3 (EPR-3) guidelines (33% based on albuterol use and asthma symptoms). Finally, visual identification of mouse infestation was associated with active steps taken to mitigate mouse exposure (P = 0.007). Conclusion: Implementation of new Asthma Management Guidelines: Focused Updates 2020 by the National Institutes of Health will require additional aeroallergen education for individuals with asthma who do not recognize that cockroaches, rats, and mice can cause asthma symptoms, do not know the definition of an allergen, and do not correctly perceive asthma control status. Environmental assessment with education addressing these could hopefully decrease additional pharmaceutical needs.

Recommendations for Clinicians to Combat Environmental Disparities in Pediatric Asthma: A Review

TOPIC IMPORTANCE

Asthma is a common and complex lung disease in children, with disproportionally higher prevalence and related adverse outcomes among children in racial and ethnic minority groups and of lower socioeconomic position. Environmental factors, including unhealthy housing and school-based exposures, can contribute to increased asthma morbidity and widening disparities. This underscores a significant environmental justice issue and suggests the need for clinical interventions to reduce sources of environmental exposures and ultimately diminish the observed disparities in childhood asthma.

REVIEW FINDINGS

Unhealthy housing conditions, including secondhand tobacco smoke, allergen exposure, and indoor air pollution, can exacerbate asthma symptoms in children. Although unhealthy housing can occur anywhere, such situations most frequently occur in urban, low-income environments where renting is common. To reduce environmental triggers, clinicians can recommend smoking cessation, cleaning techniques to mitigate exposure, and even directly contacting landlords to address poor housing conditions. Children spend much of their time in schools, where this built environment is also a source of asthma triggers (eg, poor ventilation) and allergens (eg, mold and pests, chemicals). As such, a multidisciplinary approach is needed to adequately address the burden of childhood asthma to equitably reduce disparities to both harmful exposures and negative health outcomes.

SUMMARY

Racial, ethnic, and socioeconomic disparities exist in asthma morbidity in children, and such disparities are driven in part by environmental factors at the housing and school level. Clinicians can make evidence-based recommendations to drive effective exposure reduction strategies to mitigate asthma morbidity and reduce observed disparities.

Construction of a Hybrid Vaccine Based on Der f 35-Derived Peptides with Reduced Allergenicity

INTRODUCTION

House dust mite is the primary trigger of allergic respiratory diseases worldwide, and allergen-specific immunotherapy (AIT) is the only disease-modifying treatment in the clinic. The use of allergen molecules instead of extracts is a promising strategy in AIT. In this study, we constructed a peptide hybrid vaccine against the major mite allergen Der f 35 and verified its hypoallergenicity, making it to be a promising candidate for AIT of mite allergy.

METHODS

The gene encoding Der f 35 was retrieved and synthesized. The hypoallergenic peptide fragments derived from the B-cell epitopes were synthesized based on the predicted profiles of B-cell or T helper-cell epitopes in Der f 35, they were verified by immunoglobulin E (IgE)-reaction test and fused to non-allergenic protein carrier to form the hybrid vaccine. Both the wild-type Der f 35 and the designed vaccine were expressed in Escherichia coli and purified by chromatography; their IgE-binding activity was compared by indirect enzyme-linked immunosorbent assay (ELISA), Western blot, inhibition ELISA, and basophil activation test (BAT). The blocking immunoglobulin G (IgG) against the designed vaccine was raised in rabbits and its ability to inhibit IgE binding of Der f 35 was evaluated by ELISA. The vaccine's effects on peripheral blood mononuclear cells (PBMCs) were investigated.

RESULTS

A total of 29 out of 60 (48.33%) IgE-positive sera against Der f 35 were screened. Five peptide fragments (residue 39-42, 60-67, 73-107, 111-118, 126-143) from Der f 35 were selected as candidates, in which four peptides exhibited almost no IgE reactivity and the fragment 73-107 had weak reactions. Only 5.98-24.02% inhibition rates could be achieved by the peptides when compared with Der f 35 (97.32%). The designed vaccine migrated at approximately 30 kDa by SDS-PAGE. The IgE-ELISA revealed a significant reduction in IgE-binding activity to the vaccine when compared to wild-type Der f 35 (p < 0.0001); the decreased allergenicity was further confirmed by IgE-Western blot, inhibition ELISA, and BAT, respectively. The IgE-reactivity of Der f 35 could be blocked by the vaccine-induced IgG (p < 0.01). The levels of IL-5 and IL-13 from PBMCs were significantly decreased after stimulation by the vaccine than that by Der f 35 (p < 0.05).

CONCLUSION

The designed B-cell epitope vaccine of Der f 35 showed greatly diminished allergenicity and Th2 activity. It could be an effective and safe candidate to prevent allergic adverse reactions during the immunotherapy of mite allergy and merits the further study.

Minimizing Indoor Allergen Exposure: What Works?

PURPOSE OF REVIEW

Allergic rhinitis and asthma morbidity has been linked to indoor allergen exposure. Common indoor allergens include dust mites, cats, dogs, rodents, and cockroaches. These allergens are ubiquitous and often difficult to remove from the home, making long-lasting reduction strategies difficult to achieve. Identifying strategies for reducing the presence of indoor allergens in homes could be utilized to decrease allergic disease burden, improve symptomology, reduce healthcare costs, and improve patients' quality of life.

RECENT FINDINGS

Studies have yielded mixed results with regard to specific environmental control measures in reducing indoor allergen levels and in improving clinical outcomes of allergic disease. In this review, we assess the available evidence of the effectiveness of environmental control measures in reducing indoor allergens and the potential clinical impact of these measures.

[Medical clinical diagnostics for indoor mould exposure - Update 2023 (AWMF Register No. 161/001)]

This article is an abridged version of the updated AWMF mould guideline "Medical clinical diagnostics in case of indoor mould exposure - Update 2023", presented in July 2023 by the German Society of Hygiene, Environmental Medicine and Preventive Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin, GHUP), in collaboration with German and Austrian scientific medical societies, and experts. Indoor mould growth is a potential health risk, even if a quantitative and/or causal relationship between the occurrence of individual mould species and health problems has yet to be established. There is no evidence for a causal relationship between moisture/mould damage and human diseases, mainly because of the ubiquitous presence of fungi and hitherto inadequate diagnostic methods. Sufficient evidence for an association between moisture/mould damage and the following health effects has been established for: allergic respiratory diseases, allergic rhinitis, allergic rhino-conjunctivitis, allergic bronchopulmonary aspergillosis (ABPA), other allergic bronchopulmonary mycosis (ABPM), aspergilloma, Aspergillus bronchitis, asthma (manifestation, progression, exacerbation), bronchitis (acute, chronic), community-acquired Aspergillus pneumonia, hypersensitivity pneumonitis (HP; extrinsic allergic alveolitis (EEA)), invasive Aspergillosis, mycoses, organic dust toxic syndrome (ODTS) [workplace exposure], promotion of respiratory infections, pulmonary aspergillosis (subacute, chronic), and rhinosinusitis (acute, chronically invasive, or granulomatous, allergic). In this context the sensitizing potential of moulds is obviously low compared to other environmental allergens. Recent studies show a comparatively low sensitization prevalence of 3-22,5 % in the general population across Europe. Limited or suspected evidence for an association exist with respect to atopic eczema (atopic dermatitis, neurodermatitis; manifestation), chronic obstructive pulmonary disease (COPD), mood disorders, mucous membrane irritation (MMI), odor effects, and sarcoidosis. (iv) Inadequate or insufficient evidence for an association exist for acute idiopathic pulmonary hemorrhage in infants, airborne transmitted mycotoxicosis, arthritis, autoimmune diseases, cancer, chronic fatigue syndrome (CFS), endocrinopathies, gastrointestinal effects, multiple chemical sensitivity (MCS), multiple sclerosis, neuropsychological effects, neurotoxic effects, renal effects, reproductive disorders, rheumatism, sick building syndrome (SBS), sudden infant death syndrome, teratogenicity, thyroid diseases, and urticaria.The risk of infection posed by moulds regularly occurring indoors is low for healthy persons; most species are in risk group 1 and a few in risk group 2 (Aspergillus fumigatus, A. flavus) of the German Biological Agents Act (Biostoffverordnung). Only moulds that are potentially able to form toxins can be triggers of toxic reactions. Whether or not toxin formation occurs in individual cases is determined by environmental and growth conditions, water activity, temperature and above all the growth substrates.In case of indoor moisture/mould damage, everyone can be affected by odor effects and/or mood disorders.However, this is not an acute health hazard. Predisposing factors for odor effects can include genetic and hormonal influences, imprinting, context and adaptation effects. Predisposing factors for mood disorders may include environmental concerns, anxiety, condition, and attribution, as well as various diseases. Risk groups to be protected particularly regarding infection risk are immunocompromised persons according to the classification of the German Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, KRINKO) at the Robert Koch-Institute (RKI), persons suffering from severe influenza, persons suffering from severe COVID-19, and persons with cystic fibrosis (mucoviscidosis); with regard to allergic risk, persons with cystic fibrosis (mucoviscidosis) and patients with bronchial asthma must be protected. The rational diagnostics include the medical history, physical examination, and conventional allergy diagnostics including provocation tests if necessary; sometimes cellular test systems are indicated. In the case of mould infections, the reader is referred to the specific guidelines. Regarding mycotoxins, there are currently no useful and validated test procedures for clinical diagnostics. From a preventive medical point of view, it is important that indoor mould infestation in relevant magnitudes cannot be tolerated for precautionary reasons.For evaluation of mould damage in the indoor environment and appropriate remedial procedures, the reader is referred to the mould guideline issued by the German Federal Environment Agency (Umweltbundesamt, UBA).

Outdoor aeroallergen impacts on asthma exacerbation among sensitized and nonsensitized Philadelphia children

Background

Outdoor aeroallergens, such as pollens and molds, are known triggers of asthma exacerbation; however, few studies have examined children's aeroallergen response based on sensitization.

Objective

Our aim was to compare the relative impact of aeroallergen levels on asthma exacerbation between pediatric patients with asthma who tested positive or negative for sensitization to particular allergens.

Methods

A case-crossover design study was conducted to examine associations between outdoor aeroallergen levels and asthma exacerbation events among children living in Philadelphia, Pennsylvania, who were treated within a large pediatric care network. Sensitization to common allergens was characterized in a subset of patients with asthma exacerbation who had undergone skin prick testing (5.5%). Odds ratios (ORs) and 95% CIs were estimated in all patients with asthma exacerbation and in those sensitized or not sensitized to aeroallergens.

Results

Children who were sensitized to a particular allergen had higher odds of asthma exacerbation with exposure to the allergen (ie, early-season tree pollen, oak tree pollen, early-season weed pollen, and late-season molds) than did all patients with asthma or nonsensitized patients. For example, the association between early-season tree pollen and asthma exacerbation among sensitized children (>90th percentile vs ≤25th, OR = 2.28 [95% CI = 1.23-4.22]) was considerably stronger than that estimated among all patients (OR = 1.34 [95% CI = 1.19-1.50]), and it was also substantially different from the lack of association seen among nonsensitized children (OR = 0.89 [95% CI = 0.51-1.55] [P value for heterogeneity = .03]).

Conclusion

More prevalent allergy testing may be useful for prevention of asthma exacerbation by informing interventions targeted to sensitized children and tailored for particular aeroallergens.

Intranasal administration of a synthetic TLR4 agonist INI-2004 significantly reduces allergy symptoms following therapeutic administration in a murine model of allergic sensitization

Introduction

Atopic diseases have been steadily increasing over the past decades and effective disease-modifying treatment options are urgently needed. These studies introduce a novel synthetic Toll-like receptor 4 (TLR4) agonist, INI-2004, with remarkable efficacy as a therapeutic intranasal treatment for seasonal allergic rhinitis.

Methods

Using a murine airway allergic sensitization model, the impact of INI-2004 on allergic responses was assessed.

Results

One or two intranasal doses of INI-2004 significantly reduced airway resistance, eosinophil influx, and Th2 cytokine production - providing strong evidence of allergic desensitization. Further investigations revealed that a liposomal formulation of INI-2004 exhibited better safety and efficacy profiles compared to aqueous formulations. Importantly, the liposomal formulation demonstrated a 1000-fold increase in the maximum tolerated intravenous dose in pigs. Pre-clinical GLP toxicology studies in rats and pigs confirmed the safety of liposomal INI-2004, supporting its selection for human clinical trials.

Discussion

These findings lay the groundwork for the ongoing clinical evaluation of INI-2004 in allergic rhinitis as a stand-alone therapy for individuals poly-sensitized to multiple seasonal allergens. The study underscores the significance of innovative immunotherapy approaches in reshaping the landscape of allergic rhinitis management.

Effectiveness of Asthma Home Management Manual and Low-Cost Air Filter on Quality of Life Among Asthma Adults: A 3-Arm Randomized Controlled Trial

Background

Asthma affects the quality of life (QoL) of millions of people worldwide. Effective control is paramount to a decline in prevalence and severity. To address this, we aimed to investigate the effectiveness of an asthma home management manual and low-cost air filter in improving resource-limited settings.

Patients and Methods

This randomized controlled trial was conducted between March to July 2022. The participants were 18-55 years old outpatient with asthmatic patients. A total of 114 participants were recruited and randomly assigned to three groups: home management only, home management and air filtering, and control. Validated measurement tools were applied, and the Wilcoxon test was used to evaluate changes in QoL.

Results

Asthma burden was found in at least one-third of participants in each group. At baseline, there was no difference in mAQLQ scores among participants in all group allocations (p-value > 0.05), and the air filter group had an increase in the total mAQLQ score (p-value = 0.044) and post-intervention activity quality of life (p-value = 0.002). The environmental quality of life increased post-intervention (p-value = 0.004) and remained higher after four weeks of follow-up compared to baseline (p-value = 0.041) in the home management group participants.

Conclusion

The findings indicate that the enforcement of a home management manual and the application of low-cost filters in air circulation systems offer advantages in improving the quality of life of patients with moderate and mild asthma.

AWMF mold guideline "Medical clinical diagnostics for indoor mold exposure" - Update 2023 AWMF Register No. 161/001

None.

Pediatric asthma comorbidities: Global impact and unmet needs

Real-world data on the range and impact of comorbid health conditions that affect pediatric asthma are scant, especially from developing countries. Lack of data hinders effective diagnosis, treatment, and overall management of these complex cases. We, hereby, describe the common pediatric asthma comorbid conditions in terms of evidence for association, potential mechanisms of impact on asthma control, and treatment benefit. Obesity, upper airway allergies, dysfunctional breathing, multiple sensitizations, depressive disorders, food allergy, and gastro-esophageal reflux are common associations with difficult-to-treat asthma. On the other hand, asthma symptoms and/or management may negatively impact the well-being of children through drug adverse effects, worsening of anaphylaxis symptoms, and disturbing mental health. Awareness of these ailments may be crucial for designing the optimum care for each asthmatic child individually and may ultimately improve the quality of life of patients and their families. A multidisciplinary team of physicians is required to identify and manage such comorbidities aiming to mitigate the over-use of asthma pharmacotherapy. Asthma research should target relevant real-world difficulties encountered at clinical practice and focus on interventions that would mitigate the impact of such comorbidities. Finally, policymakers and global healthcare organizations are urged to recognize pediatric asthma control as a healthcare priority and allocate resources for research and clinical interventions. In other words, global asthma control needs support by compassionate scientific partnership.

Allergic rhinitis: Review of the diagnosis and management: South African Allergic Rhinitis Working Group

BACKGROUND

Allergic rhinitis (AR) has a significant impact on the community as a whole with regard to quality of life and its relationship to allergic multi-morbidities. Appropriate diagnosis, treatment and review of the efficacy of interventions can ameliorate these effects. Yet, the importance of AR is often overlooked, and appropriate therapy is neglected. The availability of effective medications and knowledge as to management are often lacking in both public and private health systems.

METHODS

This review is based on a comprehensive literature search and detailed discussions by the South African Allergic Rhinitis Working Group (SAARWG).

RESULTS

The working group provided up-to-date recommendations on the epidemiology, pathology, diagnosis and management of AR, appropriate to the South African setting.

CONCLUSION

Allergic rhinitis causes significant, often unappreciated, morbidity. It is a complex disease related to an inflammatory response to environmental allergens. Therapy involves education, evaluation of allergen sensitisation, pharmacological treatment, allergen immunotherapy (AIT) and evaluation of the success of interventions. Regular use of saline; the important role of intranasal corticosteroids, including those combined with topical antihistamines and reduction in the use of systemic steroids are key. Practitioners should have a thorough knowledge of associated morbidities and the need for specialist referral.Contribution: This review summarises the latest developments in the diagnosis and management of AR such that it is a resource that allows easy access for family practitioners and specialists alike.

Difficult-to-treat asthma patients from ethnic minority groups in central England are at an enhanced risk of house dust mite sensitisation

BACKGROUND

House dust mite (HDM) is the most common sensitising allergen in asthma. Ethnic minority groups (EMGs) in the UK are more likely to live in deprived conditionings with a greater exposure to HDM and other aero-allergens.

AIM

To compare the ethnicity-based patterns of sensitisation to aero-allergens and the impact of ethnicity on clinical outcomes in patients with difficult-to-treat asthma (DTA).

METHODS

Data of patients with DTA were extracted from the registry of the Birmingham Regional Severe Asthma Service (BRSAS), which have a catchment population of 7.3million from Central England. Patients from White and EMG backgrounds were compared in terms of the prevalence of atopy, total serum immunoglobulin E (IgE), specific serum IgE (ssIgE) and asthma related clinical outcomes. Logistic regression analysis was conducted to explore ethnicity-based risk factors for HDM sensitisation.

RESULTS

A total of 1272 patients [White 1016 (79.9%), EMG 256 (20.1%) EMG] with a median age of 51 years (range 16-97) were included in the analysis. Patients from EMG were more likely (64%) to reside in the worst scale of index of multiple deprivation (IMD) than the White patients (25.5%), p < 0.0001. Positive HDM sensitisation was more prevalent in the EMG than in the White group [142/216 (66%) versus 375/842 (45%), p < 0.0001]. The median HDM ssIgE level was higher in the EMG than in the White group [3.0 KUA/L (IQR 0.06, 11.5) versus 0.1 (0.01, 3.0), p < 0.000001]. The odds ratio for positive sensitisation to HDM conveyed by the EMG status was 2.61 (95%CI, 1.8-3.8), p < 0.0001. Compared to the White group, the EMG had higher median total serum IgE [326 KU/L (115, 971) versus 114 (29.8, 434.8), p < 0.000001], higher blood eosinophil count (0.36 × 109 (0.18, 0.62) versus 0.23 (0.1,0.47), p < 0.000001), were marginally more atopic (79.2% vs. 75.6%, p = 0.098) and were less likely to being on maintenance oral corticosteroids (22% vs. 39.7%, p < 0.0001).

CONCLUSION

In this DTA cohort, positive HDM sensitisation was greater amongst the EMG than the White patients. The EMG status was a significant risk factor for HDM sensitisation.

Cockroach allergy: Understanding complex immune responses to develop novel therapies

Cockroach allergy is associated with the development of asthma. The identification of cockroach allergens, which began in the 1990 s, is an ongoing process that has led to the current listing of 20 official allergen groups in the WHO/IUIS Allergen Nomenclature database. The function and structure of some of these allergens has been determined and define their natural delivery into the environment and their allergenicity. Analysis of antigenic determinants by X-ray crystallography and rational design of site-directed mutagenesis led to the identification of IgE binding sites for the design of molecules with reduced IgE reactivity and T cell modulatory capacity. New developments in recent years include component analyses of B and T cell reactivity and a recent cockroach immunotherapy trial, CRITICAL, that will contribute to understand the immune response to cockroach and to define future directions for cockroach allergy diagnosis and immunotherapy.

Moisture damage and fungal contamination in buildings are a massive health threat - a surgeon's perspective

OBJECTIVES

Indoor air toxicity is of major public health concern due to the increase in humidity-induced indoor mould exposure and associated health changes. The objective is to present evidence for the causality of health threats and indoor mould exposure.

METHODS

PubMed search on the following keywords: dampness, mould, indoor air quality, public health, dampness, and mould hypersensitivity syndrome, sick building syndrome, and building-related illness as well as information from the health authorities of Bavaria and North Rhine-Westphalia, the Center of Disease Control (CDC), World Health Organisation (WHO), and guidelines of professional societies.

RESULTS

The guidelines of professional societies published in 2017 are decisive for the assessment of the impact of mould pollution caused by moisture damage on human health and for official regulations in Germany. Until 2017, a causal connection between moisture damage and mould exposure could usually only be established for pulmonary diseases. The health risk of fungal components is apparent as documented in the fungal priority pathogens list (FPPL) of the WHO. Since 2017, studies, especially in Scandinavia, have proved causality between moisture and mould exposure not only for pulmonary diseases but also for extrapulmonary diseases and symptoms. This was made possible by new test methods for determining the toxicity of fungal components in indoor air. Environmental medical syndromes, e.g., dampness and mould hypersensitivity syndrome (DMHS), sick building syndrome (SBS), building-related symptoms (BRS), and building-related illness (BRI), and fungal pathogens, e.g., Aspergillus fumigatus, pose a major threat to public health.

CONCLUSION

There is evidence for the causality of moisture-induced indoor moulds and severe health threats in these buildings. According to these findings, it is no longer justifiable to ignore or trivialize the mould contamination induced by moisture damage and its effects on pulmonary and extrapulmonary diseases. The health and economic implications of these attitudes are clear.

Using Component-Resolved Diagnosis to Characterize the Sensitization to Specific Cat and Dog Allergens in Patients with Allergic Respiratory Diseases in Catalonia, Spain

INTRODUCTION

Sensitization to cat and dog allergens is common in patients with allergic respiratory diseases. The study objective was to determine the prevalence of immunoglobulin E (IgE) sensitization to specific cat and dog allergens using component-resolved diagnosis (CRD) in patients with allergic respiratory diseases plus cat and/or dog sensitization.

METHODS

We included 87 patients aged 8-62 years, diagnosed with allergic asthma and/or rhinitis plus cat and/or dog sensitization, and attended at the allergy section of a tertiary hospital in Badalona (Catalonia, Spain). We used CRD to determine IgE sensitization to specific cat/dog allergens and skin prick tests (SPTs) to determine differences between diagnostic test results.

RESULTS

Patients were monosensitized to cats (20.7%) or dogs (3.4%) or sensitized to both (75.9%). The highest positive allergen rates were for Fel d 1 (91.7%) and Fel d 4 (41%) in patients sensitized to cat allergens and for Can f 5 (80%) and Can f 1 (70%) in those sensitized to dog allergens. CRD and SPT results differed somewhat: 16.1% and 27.6% of patients CRD positive for cat or dog sensitization, respectively, were SPT negative, and 6.9% SPT positive for dog sensitization were CRD negative. Few statistically significant relationships were found between any allergen components and any respiratory disease characteristic or contact with furry animals.

CONCLUSIONS

CRD may be used to determine the prevalence of IgE sensitization to specific cat and dog allergens in patients with allergic respiratory diseases plus cat and/or dog sensitization. As SPT may not correctly identify all patients sensitized to cats and dogs, our results support the use of CRD.

Indoor Aeroallergen Sensitization and Associated Factors in Hospitalized Children with Asthma Exacerbations

Background

Allergic asthma represents the most popular phenotype of childhood asthma and is characterized by eosinophilic airway inflammation associated with specific immunoglobulin E (IgE) antibodies sensitization to various allergens, as evidenced by serology or skin prick test.2 Sensitization to indoor aeroallergens is associated with severe asthma and severe asthma exacerbations.

Objective

This study aimed to identify the prevalence of aeroallergen sensitization and its associated factors in children with an asthma exacerbation in Vietnam.

Methods

A cross-sectional study was conducted at Children's Hospital 1, Ho Chi Minh City (HCMC). Children who were aged 3 to 15 and admitted to the hospital with moderate or severe asthma exacerbation were recruited to the study. Data was collected from interviews and medical records. SPT was used to identify aeroallergen sensitization. The association between school-age, living area, and passive smoking with the odds of aeroallergen sensitization was assessed using a multivariable logistic regression.

Results

The prevalence of aeroallergen sensitization was 82.6% and this figure in school-age children was higher than that in preschool-age ones (93.8% vs 72.1%, p=0.001). School-age, living in HCMC, and passive smoking significantly increased the odds of aeroallergen sensitization in asthmatic children with adjusted OR [95%CI] as 6.9 [2.1-23.3], 4.1 [1.5-11.5], and 2.9 [1.0-8.4], respectively. Asthmatic children with aeroallergen sensitization required more hours to resolve an asthma exacerbation than those without (22.4 vs 15.2, p=0.006).

Conclusion

Aeroallergen sensitization was common in hospitalized children with moderate or severe asthma exacerbation. It is necessary to establish environmental policy and screening practices of aeroallergen sensitization to improve the quality of asthma management for Vietnamese children.