Atopic Dermatitis: Disease Characteristics and Comorbidities in Smoking and Nonsmoking Patients from the TREATgermany Registry.

Background Atopic dermatitis (AD) is a chronic inflammatory skin disease with a multifactorial genesis including genetic predispositions and environmental risk and trigger factors. One of the latter possibly is smoking, indicated by an increased prevalence of AD in adults and children that are actively or passively exposed to cigarette smoke. Objectives In this study AD characteristics and its atopic comorbidities are compared in smoking and nonsmoking AD patients. Methods TREATgermany is a non-interventional clinical registry which includes patients with moderate to severe AD in Germany. Baseline data of patients included into TREATgermany from inception in June 2016 to April 2020 in 39 sites across Germany was analyzed comparing AD disease characteristics and comorbidities in smokers versus non-smokers. Results Of 921 patients, 908 (male: 58.7%) with a mean age of 41.9 ± 14.4 reported their smoking status. The objective Scoring of Atopic Dermatitis (oSCORAD) did not differ between smokers (n=352; 38.8%) and nonsmokers, however lesions' intensity of oozing/crusts and excoriations as well as patient global assessment scores (PGA) of AD severity were higher in smoking as opposed to nonsmoking patients. Smokers reported a lower number of weeks with well-controlled AD and more severe pruritus than nonsmokers. Total IgE levels were more elevated in smokers and they displayed a younger age at initial diagnosis of bronchial asthma. After adjustment for potential confounders, the increased intensity of oozing/crusts, the reduced number of weeks with well-controlled AD and the greater pruritus remained different in smokers compared to nonsmokers. In addition, smoking patients with adult-onset AD showed a 2.5 times higher chance of involvement of the feet. Conclusions German registry data indicate that AD patients who smoke have a higher disease burden with a different distribution pattern of lesions in adult-onset AD.