Study finds a strong bidirectional link between vitiligo and melasma

A recent study published in the Indian Journal of Dermatology, Venereology and Leprology uncovered a significant and previously underexplored association between vitiligo and melasma. The study involved over 1,43,000 individuals to robustly demonstrate a bidirectional relationship between these two conditions, raising important questions for dermatological diagnosis and treatment.

Vitiligo, characterized by depigmented white patches on the skin, and melasma, marked by dark, blotchy facial discoloration, are generally considered biologically distinct. The new research challenged this assumption, showing that individuals with one condition are at higher risk of developing the other, regardless of traditional risk factors such as hormonal therapies, thyroid dysfunction, or specific treatments like phototherapy and hydroquinone.

The study analyzed data from 24,436 vitiligo patients and 1,19,205 matched comparators using both retrospective cohort and nested case-control designs. Over a follow-up period, the incidence of melasma was 1.38 per 1000 person-years in patients with vitiligo, when compared to 0.88 per 1000 person-years in the non-vitiligo group. This translates to a 60% higher risk of developing melasma among those with vitiligo, even after adjusting for potential confounders (adjusted hazard ratio [HR] 1.58, 95% CI 1.35–1.86).