Lack of association between indoor allergen sensitization and asthma morbidity in inner-city adults

Background

Sensitivity and exposure to indoor allergens is associated with increased asthma morbidity in inner-city children. However, it is unknown whether sensitization is associated with worse asthma in adults.

Objective

To evaluate the relationship between sensitization and asthma morbidity in urban adults.

Methods

We prospectively studied 245 adults with persistent asthma recruited from an inner-city clinic. Sensitization to indoor allergens was evaluated by specific IgE antibodies measured at enrollment. Data on asthma control, asthma-related emergency department visits, hospitalizations, and oral steroid use were collected at baseline and at 1-month and 3-month follow-up contacts. Univariate, stratified, and multiple regression analyses were used to compare asthma morbidity in sensitized and nonsensitized patients after controlling for self-reported exposure and other potential confounders.

Results

The study cohort consisted predominantly of low income, minority patients with high rates of resource utilization. The prevalences of sensitization to cockroach, dust mite, cat, mold, and mouse were 60%, 43%, 41%, 21%, and 14%. On univariate analyses, patients sensitized to each allergen did not have worse asthma control or higher resource utilization compared with nonsensitized individuals. Stratified and multivariate analyses also showed no association between sensitization and several measures of asthma morbidity even after controlling for self-reported exposure to indoor allergens and other potential confounders.

Conclusion

Sensitization to indoor allergens does not appear to be associated with increased asthma morbidity in inner-city adults.

Clinical implications

These findings suggest that efforts to improve asthma control among urban populations should focus on other modifiable risk factors for morbidity.

Key words: Asthma, sensitization, inner-city, morbidity, allergy, IgE

Abbreviations used: ACQ, Asthma Control Questionnaire, ED, Emergency department