Photodynamic therapy with topical application of 5-aminolevulinic acid in the treatment of actinic keratoses: an initial clinical study.

BACKGROUND: The incidence of actinic keratoses (AK) is rising and there is still a need for therapeutic alternatives. OBJECTIVE: To demonstrate the efficacy and tolerability of topical photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) in the treatment of AK. METHODS: Ten patients with 36 lesions (19 at hands and arms, 17 on the head) received ALA-PDT once (occlusive application of a 10% ALA emulsion for 6 h, irradiation with red light, 580-740 nm, 150 J/cm2) and were then monitored for 3 months. Therapeutic efficacy was judged using a score evaluating infiltration and keratosis of AK. RESULTS: After 28 days, significantly lower score sums were observed (head: mean = 15%; hand: mean = 67%) compared to the initial score (100%). Complete remission was achieved in 71% of AK localized on the head. No notable side effects were observed. CONCLUSION: This study demonstrated the potential of good efficacy and tolerability in the treatment of AK using topical ALA-PDT. How efficacy for lesions on the hand can be improved and whether PDT is able to concur with established treatment modalities remains to be shown in further studies.