Topical 5-aminolevulinic acid photodynamic therapy for recalcitrant facial flat warts

Photodynamic therapy (PDT) uses light energy to excite a photosensitizing agent, leading to production of reactive oxygen species, which exert cytotoxic effects on targeted cells. PDT has emerged as a promising therapeutic modality for the treatment of flat warts caused by human papillomavirus (HPV) infection, by targeting infected keratinocytes and inactivating nonenveloped viral particles. Some patients with recalcitrant flat warts on the face who have poor response to traditional treatment often seek effective therapy to have the warts removed. In this report, we retrospectively evaluated the efficacy of topical 10% 5-aminolevulinic acid PDT (ALA-PDT) in the treatment of 15 patients with recalcitrant facial flat warts. Patients received treatment once every two weeks for a total of two or three sessions. At 24 weeks after the start of treatment, 86.67% of patients showed complete or excellent response. Further more, the remission rate of 100% lesion clearance was 46.67% (seven patients), and the remission rate of 70-100% lesion clearance was 40.00% (six patients). None of the patients experienced disease recurrence or progression. The adverse reactions were generally well tolerated by the patients and mostly resolved in a few days without special treatment. Our findings showed that topical 10% ALA-PDT is a safe and effective treatment for recalcitrant facial flat warts.