Photodynamic therapy of acne vulgaris using methyl aminolaevulinate: a blinded, randomized, controlled trial

Background Inflammatory acne vulgaris is a very common condition, particularly in adolescents and young adults, and new effective and well-tolerated treatments are needed. Objectives To evaluate the efficacy and tolerability of methyl aminolaevulinate-based photodynamic therapy (MAL-PDT) in patients with moderate to severe facial acne vulgaris in a randomized, controlled and investigator-blinded trial. Methods Twenty-one patients were assigned to the treatment group and 15 patients to the control group. The treatment group received two MAL-PDT treatments, 2 weeks apart. Both groups were evaluated 4, 8 and 12 weeks after treatment. Efficacy evaluation included changes from baseline in numbers of noninflammatory and inflammatory lesions, changes from baseline in global acne severity grade and clinical assessments of clinical improvement by patient and evaluating dermatologist. Pain scores during treatment and local adverse effects were also evaluated. Results Twelve weeks after treatment the treatment group showed a 68% reduction from baseline in inflammatory lesions vs. no change in the control group (P = 0.0023). We found no reduction in number of noninflammatory lesions after treatment. All patients experienced moderate to severe pain during treatment and developed severe erythema, pustular eruptions and epithelial exfoliation. Seven patients did not receive the second treatment due to adverse effects. Conclusions MAL-PDT proved to be an efficient treatment for inflammatory acne. The treatment was associated with severe pain during treatment and severe adverse effects after treatments. Efforts must be made to optimize the treatment regimen and to avoid adverse effects.