Do atopy predict severity of asthma

Introduction: Atopy is the tendency to develop an immunoglobulin E antibody response to common allergens. Even though atopy is strongly considered as predisposing factor of asthma, not all asthma is allergic in nature. The relationship between atopy and asthma severity is complex and not well established. Hypothesis: Patients with atopy have severe asthma and poor control compared to non-atopics. Methods: 108 patients with asthma diagnosed in specialist asthma clinic were randomly studied retrospectively for asthma severity and control. Non-Asthma cases were excluded using either history, lung function tests or normal bronchial challenge test. Patients with total IgE >100 IU/ml were considered atopic. Statistical analysis was performed using Unpaired t-test or Mann-Whitney U test for continuous variables. Results: Mean age of "62" Non-atopic patients was 51.06 yrs and "46" Atopic patients was 46.91 yrs. Atopic patients were on higher treatment for asthma with mean British thoracic society (BTS) step of 3.89 compared to non-atopic patients, BTS step of 3.45; P=0.024. 39% of Atopics were taking oral steroids compared to 16% of non- atopics; P=0.03. There is no statistical significance between the two groups in Forced expiratory volume in 1 second(Fev1), P=0.55; Fev1%, P=0.6; Asthma control test (ACT), P=0.33; Asthma quality of life questionnaire(AQLQ), P=0.17; Hospital Asthma Admissions/ yr, P=0.70; Mean inhaled steroid dose in 24hrs, P=0.58 and Usage of inhaled steroid and long acting beta agonist combination inhalers, P=0.71. Conclusions: Even though there is no significant association between Atopy and severity or control of asthma, These patients are younger and were using more oral steroids there by scoring high on BTS step for asthma severity.