Prevalence and Determinants of Seborrhoeic Dermatitis in a Middle‐aged and Elderly Population: the Rotterdam Study

Seborrheic dermatitis is a common skin disorder occurring on the scalp, face and chest and is characterized by inflammation and a greasy scaling. It is not clear what causes seborrheic dermatitis, but it is thought that overgrowth of Malassezia yeasts contributes to developing seborrheic dermatitis. Several other factors have been associated with the disease as well; age, sex, obesity, skin colour, stress, depression, education level, hypertension, climate, xerosis cutis, alcohol and tobacco use have all been associated with seborrheic dermatitis, but the evidence for these associations was often not conclusive. The aim of this study was to establish which lifestyle and physiological factors are associated with seborrheic dermatitis. Data from the Rotterdam Study of middle aged and elderly people from the Netherlands, was used to investigate these previously reported factors. The rationale is that knowledge about determinants could provide new insights in the pathophysiology of seborrheic dermatitis, which might lead to preventative strategies and/or new treatment regimes. In the Rotterdam study, 5,498 participants underwent a full body skin examination, of which 788 had seborrheic dermatitis. The authors found that male sex, light skin colour, winter season and a generalised dry skin increased the likelihood of having seborrheic dermatitis and that the other factors were not associated with seborrheic dermatitis. Further, the authors conducted an analysis to investigate if the gender differences could be explained by hormonal differences, but they did not find an association between hormones and seborrheic dermatitis. Of the found associations, a dry skin seems the easiest to influence. Improving the skin barrier could therefore become a target in the treatment of seborrheic dermatitis.