Exposome Risk Factors for Vitiligo: A Systematic Evidence Review

Vitiligo is a multi-factorial autoimmune skin disorder often triggered by environmental exposures. Although the exposome has gained attention, no systematic review has fully assessed its role in vitiligo.

We aimed to evaluate evidence linking exposomal factors to vitiligo onset and progression, focusing on quantifiable associations and study quality.

A systematic search of PubMed and Embase (inception to 25 August, 2024) followed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) 2020 guidelines and was registered in PROSPERO (CRD42024529828). Eligible studies reported associations between environmental exposures and vitiligo onset, flares, or progression. Observational studies, case series, clinical trials, and pharmacovigilance reports were included. Findings were synthesized narratively.

Of 8377 records, 496 studies met inclusion criteria. Drug-associated vitiligo, particularly from immune checkpoint inhibitors, was the most robustly supported association (7-25% in patients with melanoma). Phenol-based chemicals were consistently linked to melanocyte toxicity. Coronavirus disease 2019 infection modestly increased risk (hazard ratio ≈ 1.11), while vaccination did not. Other factors such as stress (n = 113), trauma, sunburn, smoking, diet, and sleep were frequently cited but supported by lower-level evidence. Study heterogeneity, a lack of standardized outcomes, and the predominance of observational designs limited meta-analysis and causal inference.

These findings highlight the environmental triggers of vitiligo onset and progression. Drugs, chemicals, and infections are key triggers; lifestyle factors require further study.