Off-label photodynamic therapy for recalcitrant facial flat warts using topical 5-aminolevulinic acid

The facial flat wart (verruca plana) is one of the most common reasons for dermatology and primary care visits. Although there are many therapeutic modalities, no single therapy has been proven to be completely curative. Case reports and uncontrolled studies suggested that photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) can effectively treat recalcitrant facial flat warts. A total of 12 patients with recalcitrant facial flat warts were enrolled in the study. ALA gel (10 %) was applied topically to lesions and incubated for 3 h. The lesions were irradiated by an LED light of 630 ± 10 nm at dose levels of 60-100 mW/cm. Clinical assessment was conducted before and after every treatment for up to 24 weeks. Among the ten patients completing three sessions of ALA-PDT, five had complete lesions clearance, and the other five patients were significantly improved. At the 24-week follow-up, the average effective rate was 88.8 %, with no recurrences. No significant side effects were reported. A low-dose topical ALA-PDT regimen using 10 % ALA, 3 h incubation, and a red light source for three treatment sessions are suggested as the optimal scheme for the treatment of recalcitrant flat warts on the face in Chinese patients. Superior efficacy is found in elevated or active period lesions with mild side effects.