Doxycycline-Induced Phototoxicity Localized to Vitiligo-Affected and Sun-Exposed Skin.

Vitiligo is a chronic autoimmune disorder characterized by depigmented skin secondary to melanocyte loss, which may increase susceptibility to phototoxic drug reactions. We describe a case of doxycycline-induced phototoxicity selectively affecting vitiliginous and sun-exposed skin, with complete resolution after drug discontinuation. This case highlights melanin's protective role against ultraviolet-mediated injury and demonstrates that patients with pigmentary disorders may be at higher risk for localized phototoxic reactions from photosensitizing medications. Clinicians should maintain vigilance, emphasize photoprotection, and consider alternative therapies with a lower risk of phototoxicity in such populations.