Photodynamic therapy for severe facial acne vulgaris with 5% 5-aminolevulinic acid vs 10% 5-aminolevulinic acid: A split-face randomized controlled study.

Background: Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) has been described as an effective treatment for severe acne. However, very little evidence exists on the optimal concentration of ALA used in PDT for severe acne.

Objectives: To compare the efficacy and safety of PDT with 5% ALA vs 10% ALA in severe acne.

Methods: Twenty-three patients with severe facial acne were randomly assigned to receive PDT with 5% ALA or 10% ALA on the left or right side of the face. Four PDT sessions were conducted with a light dose of 96 J/cm . The reduction rates of lesion counts between the two groups were compared at the week-4 and week-12 follow-up visits. Effective rate at the week-12 visit was the primary clinical outcome. Pain and other side effects were evaluated at each visit.

Results: The decrease in inflammatory lesions in the 10% ALA group was greater than that in the 5% ALA group at both week-4 (79.2% vs 62.5%, P = 0.009) and week-12 follow-up visits (88.5% vs 78.3%, P = 0.018), while the decrease in noninflammatory lesion counts between the two groups was not statistically significant at each follow-up visit. The effective rate in the 10% ALA group was significantly higher than that in the 5% ALA group (95.7% vs 69.6%, P = 0.02). No significant difference was observed in pain scores between the two groups except in the first treatment session.

Conclusions: Photodynamic therapy using 10% ALA was more effective for severe acne than PDT using 5% ALA.