Investigating the epidemiological relationship between vitiligo and psoriasis: a population-based study

Background The association of vitiligo with psoriasis is inconsistent in the current literature. Objective To assess the bidirectional association between vitiligo and psoriasis. Methods A population-based study was performed to compare vitiligo patients ( n = 20,851) with age-, sex- and ethnicity-matched control subjects ( n = 102,475) regarding the incidence of new-onset and the prevalence of preexisting psoriasis. Adjusted hazard ratios (HRs) and adjusted odds ratios (ORs) were calculated by cox regression and logistic regression, respectively. Results The incidence rate of new-onset psoriasis was estimated at 7.9 (95% CI 6.4–9.7) and 4.7 (95% CI 4.1–5.3) cases per 10,000 person-years among patients with vitiligo and controls, respectively. Patients with vitiligo experienced an increased risk of psoriasis (fully-adjusted HR 1.71; 95% CI 1.35–2.17; P