Dermatological comorbidity in psoriasis: results from a large-scale cohort of employees.

The field of dermatological comorbidity in psoriasis is only passively explored with contradictory results. Objective of this study was to further investigate the complex field of psoriasis and associated skin diseases by identifying skin comorbidity patterns in an extensive cohort of employees in Germany. Retrospective analysis of data deriving from occupational skin cancer screenings was conducted. From 2001 to 2014 German employees between 16 and 70 years from different branches underwent single whole-body screenings by trained dermatologists in their companies. All dermatological findings and need for treatment were documented. Point prevalence rates and their 95% confidence intervals were computed. Logistic regression analysis was performed to calculate odds ratios (OR) of single dermatological diseases to occur together with psoriasis controlled for age and sex. Data from 138,930 persons (56.5% male, mean age 43.2) were evaluated. Psoriasis point prevalence was 2.0%. Of those 20.6% had unmet treatment needs of their disease. Onychomycosis was the most frequent dermatological comorbidity with a prevalence of 7.8%. Regression analysis found rosacea (OR = 1.40, 95% CI 1.13-1.72) and telangiectasia (OR = 1.25, 95% CI 1.10-1.41) to be significantly associated with psoriasis. 17.2% of psoriasis patients had at least one further finding requiring treatment. The highest treatment needs were found for onychomycosis (3.4%), tinea pedis (3.1%), and verruca plantaris (1.0%). It can be concluded that persons with psoriasis are at increased risk to suffer from comorbid skin diseases, which should be considered in treatment regimens. Particular attention should be paid to fungal diseases of the feet.