Seborrheic dermatitis (SD) prevalence is higher in men, and the skin disorder appears to be associated with fungal and bacterial diseases, according to a study published in the British Journal of Dermatology.
The study used data from voluntary company skin checks conducted between 2001 and 2016 at >500 companies in Germany. A total of 161,269 participants were included (mean age, 43.2±10.9). Participants were referred to a dermatologist in cases where treatment was required. The location and appearance of skin lesions helped dermatologists establish a clinical diagnosis of SD in all subjects. A logistic regression analysis adjusted for age and sex explored the association of additional dermatological conditions with SD.
The prevalence rate of SD in the overall cohort was 3.2%, with a significantly higher rate in men vs women (4.6% vs 1.4%, respectively; P ≤.001). Prevalence of SD was also significantly higher in older age groups (2.0% in patients aged <35 years vs 3.6% in patients aged 35-64 vs 4.4% in patients aged ≥65; P ≤.001).
The most frequently reported concomitant skin conditions included folliculitis (17.0%; 95% CI, 15.9%-18.1%), onychomycosis (9.1%; 95% CI, 8.3%-10.0%), tinea pedis (7.1%; 95% CI, 6.3%-7.8%), rosacea (4.1%; 95% CI, 3.6%-4.7%), acne (4.0%; 95% CI, 3.4%-4.5%), and psoriasis (2.7%, 95% CI 2.3%-3.2%).
According to the regression analysis, dermatological comorbidities associated with SD included folliculitis (odds ratio [OR], 2.1; 95% CI, 2.0-2.3), contact dermatitis (OR, 1.8; 95% CI, 1.1-2.8), intertriginous dermatitis (OR, 1.8; 95% CI, 1.4-2.2), rosacea (OR, 1.6; 95% CI, 1.4-1.8), acne (OR, 1.4; 95% CI, 1.2-1.7), pyoderma (OR, 1.4; 95% CI, 1.1-1.8), tinea corporis (OR, 1.4; 95% CI, 1.0-2.0), pityriasis versicolor (OR, 1.3; 95% CI, 1.0-1.7), and psoriasis (OR, 1.2; 95% CI, 1.0-1.5).
Limitations of the study included the voluntary nature of the dermatology screenings, the cross-sectional data analysis, and the lack of data on participants’ medication and internal comorbidity.
The researchers concluded that their findings suggest “the necessity of an integrated, complete dermatological diagnostics and therapy in this common skin condition is to be recommended.”
Zander N, Sommer R, Schäfer I, et al. Epidemiology and dermatological comorbidity of seborrhoeic dermatitis – population-based study in 161,000 employees [published online February 25, 2019]. Br J Dermatol. doi:10.1111/bjd.17826