Prevalence of Dermatological Disorders in Japan: A Nationwide, Cross-Sectional, Seasonal, Multicenter, Hospital-Based Study

In 2007, a comprehensive study involving 67,448 patients from 170 clinics in Japan found that eczematous and fungal diseases were the most prevalent dermatological disorders. The study revealed age-specific prevalence, with atopic dermatitis being most common in the 6-40 age group and miscellaneous eczema appearing across all ages. Gender differences were also noted, with males more prone to conditions like psoriasis and androgenic alopecia, while females were more affected by hand eczema, systemic sclerosis, and systemic lupus erythematosus. Climate factors, such as average temperatures and humidity, were found to correlate with the incidence of certain skin conditions. The study aimed to provide a detailed overview of dermatological conditions in Japan, despite acknowledging certain limitations and biases in its methodology.