Efficacy of Photodynamic Therapy with Methyl 5-aminolevulinic Acid and Red Light for Actinic Keratosis

Background: Actinic keratosis (AK) is a pre-cancerous skin lesion that has the potential to progress to squamous cell carcinoma, which generally occurs on long-term sun exposed and cosmetically sensitive areas of the face, scalp, ears and neck. Many treatment options such as surgical excision, electrosurgery, cryotherapy, topical therapy including 5-fluorouracil, imiquimod and diclofenacare are available for AK, but these can be inconvenient and unsatisfactory for patients. Recently, the efficacy of topical photodynamic therapy (PDT) has been demonstrated in a large number of clinical studies over the last several years. Objective: The aim of this study was to evaluate the efficacy and adverse effects of methyl 5-aminolevulinic acid (MAL) and red light photodynamic therapy (PDT) in the treatment of actinic keratosis. Methods: This study included 21 actinic keratosis lesions in 12 patients. After application of commercially available MAL cream (Metvix, Galderma, Hertfordshire, U.K.) under occlusion for 3 hours, the lesions were illuminated by red light from a light-emitting diode system (Aktilite lamp, PhotoCure ASA, Oslo, Norway). All patients were followed for 3 months after 2 MAL-PDT sessions. Therapeutic effectivenesswas assessed by clinical and histopathological findings. Results: Complete remission was achieved in 18 of 21 lesions (85.7%). The local adverse effects were erythema, pain, burning sensation and edema. Conclusion: This study showed that MAL-PDT using red-light is a safe and effective treatment option for AK.