Vitiligo and Crohn′s disease form an autoimmune cluster: insights from a population-based study

Background: While the coexistence of vitiligo and Crohn ' s disease (CD) has been reported in individual patients, the epidemiological association between these autoimmune conditions remains inconclusive. Objective: To assess the bidirectional association between vitiligo and CD. 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 CD. Adjusted hazard ratios (HRs) and adjusted odds ratios (ORs) were calculated by multivariable Cox regression and logistic regression, respectively. Results: The incidence rate of new-onset CD was evaluated at 3.6 (95% CI, 2.7-4.9) cases per 10,000 person-years (PY) in patients with vitiligo and 2.4 (95% CI, 2.0-2.9) cases per 10,000 PY in controls. Patients with vitiligo experienced an elevated risk of CD (fully adjusted HR, 1.60; 95% CI, 1.10-2.34; p = 0.015). Congruently, a history of preexisting CD predicted elevated odds of having subsequent vitiligo (fully adjusted OR, 1.49; 95% CI, 1.15-1.93; p = 0.002). Compared to other patients with vitiligo, those with vitiligo and comorbid CD were older and had a higher prevalence of diabetes mellitus, hyperlipidemia, and hypertension but a comparable all-cause mortality rate. Conclusions: The current study depicts a robust bidirectional association between vitiligo and CD. This knowledge is of clinical implication for physicians managing patients with both conditions. The diagnostic threshold for CD should be lowered in vitiligo patients with compatible symptoms.