Clinical patterns of vitiligo in Japan: A descriptive study using the JMDC claims database

Vitiligo is a chronic autoimmune disorder that profoundly impacts patients' quality of life. Real-world data on vitiligo in Japan are limited. This descriptive, cross-sectional study used a claims database to evaluate vitiligo prevalence, patient demographics, treatments, and comorbidities in Japanese patients with vitiligo. Patients with claims for a vitiligo diagnosis in the JMDC database from January 2010 to December 2022 were included. Annual vitiligo prevalence, comorbidities, treatments, and medical facility visits were analyzed. Of 16 947 087 patients in the database during the 13-year analysis period, a total of 26 358 patients (0.16%, 95% confidence interval 0.15-0.16) had a diagnosis of vitiligo. The standardized prevalence of vitiligo by sex and age in Japan remained generally consistent between 2010 (0.051%) and 2022 (0.056%). Atopic dermatitis was the most prevalent comorbidity. Comorbid atopic dermatitis prevalence increased between 2010 (21.8%) and 2022 (34.0%), and was highest among children aged 5-9 years. Other common comorbidities in 2022 included hypertension (10.4%), dyslipidemia (8.0%), anxiety disorder (7.4%), and psoriasis (7.0%). Topical corticosteroids were the most commonly used treatment throughout the period analyzed. Between 2010 and 2022, topical corticosteroid use decreased from 75.1% to 66.9%, and the use of narrowband ultraviolet B procedures increased from 19.2% to 28.1%. Mean duration of care was 12.9 months (standard deviation 20.5 months) and the median total number of outpatient medical facility visits was 3.0 (interquartile range 1.0-12.0). Key limitations include age and occupational biases in the JMDC database and potential misclassification of comorbidities due to off-label treatment coding. Despite limitations in using a claims database, this study demonstrates consistent vitiligo prevalence in Japan, a high comorbidity burden, and evolving treatment patterns. Findings may guide clinical practice and treatment guidelines to improve management of vitiligo in Japanese patients.