Elevated Risk of Herpes Zoster in Vitiligo Patients: A Nationwide Population‐Based Cohort Study of Taiwan

Emerging therapies for vitiligo, such as Janus kinase (JAK) inhibitors, have raised concerns about an increased risk of herpes zoster (HZ), emphasizing the need to clarify the baseline HZ risk in patients with vitiligo. This study aimed to determine whether vitiligo itself is associated with a higher risk of HZ and to identify potential modifying factors, including systemic treatments. Using Taiwan's Longitudinal Health Insurance Database from 2010 to 2022, a retrospective nationwide cohort study was conducted. Patients with vitiligo were identified through diagnostic codes and matched in a 1:4 ratio with non-vitiligo controls by age, gender, index date, and comorbidities using propensity score matching. Subgroup analyses evaluated HZ risk among patients receiving systemic treatments, including phototherapy and immunosuppressants. A total of 79 910 individuals were included after matching. During the study period, the incidence of herpes zoster was significantly higher in patients with vitiligo than in controls (7.78% vs. 2.72%, p < 0.001). After adjusting for potential confounders, vitiligo remained independently associated with an increased risk of HZ (adjusted hazard ratio [aHR]: 1.532). The risk of HZ increased with age and was higher among female patients. Subgroup analysis further revealed that vitiligo patients receiving systemic therapy had the greatest susceptibility to HZ, especially those treated with cyclosporine (aHR: 1.891), methotrexate (aHR: 1.981), and systemic corticosteroids (aHR: 1.474). In conclusion, this large population-based study demonstrates that vitiligo is an independent risk factor for herpes zoster, and systemic immunosuppressive therapies further augment this risk. Clinicians should be aware of the potentially increased vulnerability to HZ among patients with vitiligo, particularly in older or female individuals. These findings may help inform general clinical considerations regarding preventive strategies, including herpes zoster vaccination, to reduce the risk of infection-related complications in this population.