Scalp seborrheic dermatitis: prevalence and associated factors in male adolescents

Background The prevalence of seborrheic dermatitis (SD) in the general population is variable in the literature. Factors associated with SD are not well understood. Objective To verify the prevalence of scalp SD in a selected survey of male adolescents on mandatory military service and to find possible associated factors (skin color, socioeconomic level, triceps skin fold, acne, and tobacco consumption). Methods This cross-sectional study included 18-year-old male adolescents on compulsory military service in a southern Brazilian city. Scalp SD was considered as erythema and scaling in any part of the scalp. Skin color, socioeconomic level, triceps skin fold, acne, and tabagism comprised the independent variables studied in our population. Results A total of 2201 adolescents entered the study. The global prevalence of scalp SD was 11%. White skin [adjusted prevalence ratio (PR) 1.42; 95% CI 1.06-1.92; P = 0.02] and triceps skin fold >19.5 mm (adjusted PR 1.56; 95% CI 1.12-2.18; P = 0.009) were significantly associated with scalp SD. The other variables were not associated with the outcome. Conclusions Prevalence of scalp SD in our survey of male adolescents was 11%. The occurrence of scalp SD was associated with white skin and a higher body fat content.