ORIGINAL ARTICLE Xerosis is associated with asthma in men independent of atopic dermatitis and filaggrin gene mutations K.A. Engebretsen, 1, * A. Linneberg, 2,3,4 B.H. Thuesen, 2 P.B. Szecsi, 5 S. Stender, 5 T. Menn e, 1 J.D. Johansen, 1 J.P. Thyssen 1 1 National Allergy Research Centre, Department of Dermato-Allergology, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark 2 Research Centre for Prevention and Health, the Capital Region of Denmark, Glostrup, Denmark 3 Department of Clinical Experimental Research, Glostrup Hospital, University of Copenhagen, Glostrup, Denmark 4 Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark 5 Department of Clinical Biochemistry, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark *Correspondence: K.A. Engebretsen. E-mail: kristiane.aasen.engebretsen.02@regionh.dk Abstract Background Epidermal filaggrin deficiency due to common filaggrin gene (FLG) mutations causes xerosis and strongly increases the risk of atopic dermatitis and even asthma. However, it is unknown whether xerosis independent of FLG mutations could also increase the risk of asthma. Objective To evaluate whether generalized xerosis was associated with asthma, independent of atopic dermatitis and common FLG mutations in a cross-sectional study on adult Danes. Methods A total of 3396 adults from the general population participated in a health examination. Lung function and serum-specific IgE levels to inhalant allergens were measured and information on xerosis and atopic diseases was obtained by means of a questionnaire. Participants were genotypes for the three most common FLG mutations in North- ern Europeans: R501X, 2282del4 and R2447X. Results Fully adjusted logistic regression analyses showed that asthma (either current or at some point in life) was sig- nificantly associated with reporting generalized xerosis (OR 1.32; 95% CI 1.02–1.72). The association was stronger in men (OR 1.79; 95% CI 1.13–2.84) when compared to women (OR 1.18; 95% CI 0.86–1.62). Furthermore, a significant association was observed between xerosis and ‘allergic asthma’ in men (OR 2.13; 95% CI 1.08–4.19). Conclusion Our findings indicate an association between xerosis and asthma in men independent of atopic dermatitis and FLG mutations. Both facilitated allergen sensitization and secondary degradation of filaggrin following T-helper cell 2 inflammation might be key elements to understanding this relationship. Received: 7 November 2014; Accepted: 15 January 2015 Conflicts of interest None declared. Funding Sources Jacob P. Thyssen and Kristiane Engebretsen are financially supported by an unrestricted grant from the Lundbeck Foun- dation. The Health2006 study was financially supported by grants from the Velux Foundation; the Danish Medical Research Council, Danish Agency for Science, Technology and Innovation; the Aase and Ejner Danielsens Foundation; ALK-Abell  o A/S (Hørsholm, Denmark), Timber Merchant Vilhelm Bangs Foundation and Research Centre for Prevention and Health, the Capital Region of Denmark. Prior presentations The content has not been published previously and is not otherwise submitted for publication. © 2015 European Academy of Dermatology and Venereology JEADV 2015 DOI: 10.1111/jdv.13051 JEADV