2009 Southern Regional Meeting Abstracts

Purpose of Study: To identify humidity as an exacerbating factor for subjects with both asthma and allergic rhinitis compared to subjects with allergic rhinitis alone.
Methods Used: Retrospective chart review of patients seen in the Allergy and Immunology Clinic between August, 2005 and December, 2007 was done. Patients were divided into two groups: asthma with allergic rhinitis (cases) and allergic rhinitis alone (control). Data was collected on demographic variables, humidity history, medications used, allergic sensitivity to molds and house-dust mite and spirometry results in both groups. Severity of asthma is categorized on basis of medications used (Mild: Nasal steroids and Bronchodilators, Severe: Inhaled steroids and Leukotriene antagonists). Univariate analysis was performed on baseline characteristics of subjects. Odds ratios and their corresponding 95% confidence intervals were estimated using conditional logistic regression with adjustment for other variables.
Summary of Results: Data was collected from 205 patients of whom 62 % are cases. About 88 (70%) cases reported humidity as an exacerbating factor for asthma compared with only 39% of controls (P<0.0001). Multiple logistic regression analysis showed that cases were more likely to report humidity as an exacerbating factor independent of stratification by allergic sensitivity to molds and house-dust mite as compared to controls (P=0.3326). Asthma patients reported humidity as an exacerbating factor irrespective of their severity (p=0.9559).
Conclusions: Our findings suggest that humidity is an exacerbating factor for asthma, even after controlling for molds, house dust mite and asthma severity.