Dose-Response Association between Smoking and Atopic Eczema: Results from a Large Cross- Sectional Study in Adolescents.

Graif Y, German L, Ifrah A, Livne I, Shohat T.

Dermatology. 2013 May 24. [Epub ahead of print]

Abstract
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.