Vitiligo-Like Depigmentated Actinic Keratosis: A Unique Case Successfully Treated with ALA-PDT

To report the clinical manifestations and therapeutic efficacy of photodynamic therapy (PDT) in a rare case of vitiligo-like depigmented actinic keratosis (AK). A 66-year-old female presented with a 10-year history of a hypopigmented facial patch (2.5 cm diameter) and a 3-year history of central erythema with scaling. The diagnosis of AK was confirmed by dermoscopy and histopathology. Three sessions of PDT were administered using 20% 5-aminolevulinic acid (ALA) cream under occlusion followed by red light irradiation (635 nm). Complete resolution of the lesion was observed post-treatment, with partial repigmentation in the hypopigmented area. No recurrence occurred during the 1-month follow-up. ALA-PDT is effective for treating hypopigmented AK and may promote pigment restoration, providing a valuable reference for similar cases.