The Safety of Melasma Treatment in Vitiligo Patients: An International E-Delphi Study.

Vitiligo and melasma frequently coexist, creating a treatment dilemma, since agents effective for one condition can destabilize the other, and no consensus currently exists on safe management. We conducted a scoping literature review (through June 2023) on treatment of patients with concomitant vitiligo and melasma, followed by a two-round international e-Delphi survey (22 experts from 14 countries; consensus defined as ≥ 70% agreement) and a final online consensus meeting. Only one study supported the safe use of oral tranexamic acid for melasma in vitiligo patients. Expert consensus favored prioritizing vitiligo treatment, particularly when active, while incorporating patient's preferences. Targeted phototherapy is suitable for localized facial lesions of vitiligo, and non-facial vitiligo can be treated alongside melasma after covering the face. Topical calcineurin inhibitors, ruxolitinib, tretinoin, corticosteroids, and oral tranexamic acid can be used. Lasers and chemical peels were recommended only with caution by experienced pigment specialists. Until there is enough scientific evidence, hydroquinone would be replaced by other safer cosmetic lightening agents (e.g., niacinamide, ascorbic acid, thiamidol, melasyl), which show comparable efficacy with less theoretical risk. This first international consensus offers practical, patient-centered guidance for managing coexisting vitiligo and melasma, emphasizing individualized, disease-activity-based treatment sequencing. Trial Registration: PROSPERO reference number: RD42023395586 Significance. Depigmenting agents used for melasma inhibit melanogenesis, a mechanism that can further compromise the already-stressed melanocyte populations characteristic of vitiligo. This consensus gives clinicians an expert-informed pathway through a common but understudied comorbidity. It also identifies a clear research gap: controlled, mechanistic comparisons of hydroquinone against newer tyrosinase inhibitors specifically in vitiligo-prone skin are still lacking.