Risk of vitiligo in patients with SARS-CoV-2 vaccination or infection: a nationwide cohort study

Background: As recent sporadic case reports of newly developed vitiligo after SARS-CoV-2 infection or vaccination have been published, a convincing large-scale study addressing this association is warranted. Objectives: To investigate the association between SARS-CoV-2 infection or vaccination and vitiligo using the Korean National Health Insurance Service database. Materials & Methods: SARS-CoV-2-positive patients and those vaccinated against SARS-CoV-2 were recruited. In studies 1 and 2, control groups were selected based on 1:1 propensity score matching with vaccinated and SARS-CoV-2-positive patients, respectively. The occurrence of vitiligo was the main outcome. Each individual was monitored for six months. The hazard ratio (HR) for vitiligo was calculated using the Cox pro-portional hazards model. Results: In study 1, the incidence of vitiligo in the vaccination group was 2.22-fold higher than that in the non-vaccination group (adjusted HR [aHR]: 2.22; 95% confidence interval [CI]: 1.54–3.19). Rheumatoid arthritis was a risk factor for vitiligo (aHR: 1.99; 95% CI: 1.12–3.54). Conversely, two factors associated with decreased incidence of vitiligo were male sex (aHR: 0.58; 95% CI: 0.40–0.82) and rural residency (aHR: 0.68; 95% CI: 0.49–0.96). In study 2, the incidence of newly-diagnosed vitiligo was not significantly different between SARS-CoV-2-positive patients and uninfected controls (aHR: 0.95; 95% CI: 0.51–1.78). Conclusion: SARS-CoV-2 vaccination may increase the risk of developing vitiligo in South Korea, although additional studies in other countries or with extended periods are needed. Clinicians should be aware of the impact of SARS-CoV-2 infection and vaccination on autoimmune skin diseases, including vitiligo.