Optimizing treatment of acne with photodynamic therapy (PDT) to achieve long-term remission and reduce side effects. A prospective randomized controlled trial.

Abstract

Photodynamic therapy with methyl aminolevulinate (MAL-PDT) is an effective treatment of acne vulgaris, but is associated with side effects. We performed a prospective randomized split-face study aimed at optimizing MAL-PDT treatment. Patients (n\xa0=\xa033) were randomized to two or four treatments of PDT with MAL on one cheek and placebo vehicle on the other cheek, 1-2\xa0weeks apart. A 1.5-h pre-treatment with the MAL cream was followed by illumination with red light (20\xa0J/cm2). Assessments were performed before treatment and 4, 10, and 20\xa0weeks after the last treatment. In comparison to baseline, the number of inflammatory lesions at 20\xa0weeks on cheeks treated with MAL-PDT showed a relative decrease of 74% in the group with two treatments and 85% in the group with four treatments. This new treatment regimen for both MAL-PDT and red-light-only PDT, with shortened pre-treatment and reduced light dose, could be an effective modality.