The role of aryl hydrocarbon receptor agonists in the treatment of vitiligo.

Vitiligo is a chronic autoimmune disorder characterized by progressive skin depigmentation. Vitiligo significantly impacts patients' quality of life, contributing to psychological and social burdens. Despite readily available therapeutic options, many cases remain refractory to treatment, highlighting the critical need for safer and more effective therapies. Currently, ruxolitinib is the only FDA-approved medication for vitiligo; however, it carries a black box warning for serious adverse effects, including infections, malignancy, and major cardiovascular events, limiting its use. Recent studies have identified the aryl hydrocarbon receptor (AhR) as a promising therapeutic target, suggesting that AhR agonists could address the multifaceted pathogenesis of vitiligo. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search to analyze the role of AhR agonists in the treatment of vitiligo on PubMed, Cochrane, Embase, MEDLINE, and Web of Science databases on April 15, 2024. Fourteen studies met the inclusion criteria, comprising two clinical trials, two case reports, and nine basic science studies. Our search revealed that culturing AhR agonists with melanocytes upregulates melanin-synthesizing enzymes, reduces reactive oxygen species, and modulates pro-inflammatory cytokines such as IL-17A and IL-22. Tapinarof, a topical AhR agonist used commonly for the treatment of psoriasis, demonstrated clinical efficacy in repigmentation with a favorable safety profile compared to long-term steroid use. Although limited by the number of clinical studies, this review underscores the potential of using AhR agonists, such as tapinarof, as a transformative approach to vitiligo management. Future clinical trials are necessary to evaluate the safety, efficacy, and long-term outcomes of AhR agonists.
(© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)