Dose-response association between smoking and atopic eczema: Results from a large cross-sectional study in adolescents

Background: Tobacco smoking and exposure to environmental tobacco smoke (ETS) are known risk factors for asthma, but their association with atopic eczema is unclear. Objective: To investigate the association of smoking and exposure to ETS with prevalence of atopic eczema in a national sample of 13-to 14-year-olds in Israel. Methods: Cross-sectional study within the framework of the International Study on Asthma and Allergies in Childhood. Results: Complete data were available for 10,298 schoolchildren. Atopic eczema as well as asthma and allergic rhinitis were significantly more prevalent in smokers than nonsmokers. Multiple regression analysis revealed a dose-response association between smoking and atopic eczema compared to not smoking: occasional smokers, odds ratio (OR) = 1.6 (95% confidence interval (CI) = 1.2-2.3); daily smokers, OR = 2.2 (95% CI = 1.4-3.6). Exposure to ETS at home was significantly associated with asthma (OR = 1.25; 95% CI = 1.1-1.5) but not atopic eczema. Conclusions: The dose-response association between active smoking and atopic eczema in adolescents is a novel observation which deserves further consideration.