Sensitization to Species is Associated with Frequent Exacerbations in Severe Asthma

Background: Severe asthma is a largely heterogeneous disease with varying phenotypic profiles. The relationship between specific allergen sensitization and asthma severity, particularly in Asia, remains unclear. We aim to study the prevalence of specific allergen sensitization patterns and investigate their association with outcomes in a severe asthma cohort in an Asian setting.

Methods: We conducted a cross-sectional study of patients receiving step 4 or 5 Global Initiative for Asthma treatment. Univariate and multivariate analyses were performed to assess the association between sensitization to a specific identifiable allergen by skin prick test (SPT) and uncontrolled asthma (defined in our study as the use of ≥2 steroid bursts or hospitalization in the past year, a history of near-fatal asthma or evidence of airflow obstruction on spirometry).

Results: Two hundred and six severe asthma patients (mean age 45±17 years, 99 [48.1%] male) were evaluated. Of them, 78.2% had a positive SPT to one or more allergens. The most common allergen to which patients were sensitized was house dust mites ( and ). Also, 11.7% were sensitized to species. On multivariate analysis, sensitization was associated with uncontrolled asthma (odds ratio 6.07, 95% confidence interval 1.80-20.51). In particular, sensitization was independently associated with the use of ≥2 steroid bursts in the past year (odds ratio 3.05, 95% confidence interval 1.04-8.95). No similar associations of uncontrolled asthma with sensitization to any other allergens were found.

Conclusion: High allergen, specifically sensitization was observed in the Asian population with severe asthma by SPT. sensitization was specifically associated with frequent exacerbations and a greater corticosteroid requirement. An improved understanding of the severe asthma with sensitization phenotype is warranted, which is likely a subgroup of severe asthma with fungal sensitization.