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/cm(2)) 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.