Recent studies have shown that photodynamic therapy (PDT) is effective in the treatment of acne vulgaris. No studies have compared the treatment effect of aminolevulinic acid–PDT (ALA-PDT) and methyl aminolevulinate–PDT (MAL-PDT).

We sought to compare the treatment effect and tolerability of ALA-PDT versus MAL-PDT in the treatment of acne vulgaris in a controlled randomized investigator-blinded trial.

Fifteen patients with at least 12 facial inflammatory acne lesions had one split-face PDT treatment with MAL and ALA.

Twelve weeks after treatment we found a 59% decrease in inflammatory lesions from baseline, with no significant differences in effectiveness between the two treatments. All patients experienced moderate to severe pain during illumination and developed erythema, pustular eruptions, and epithelial exfoliation after treatment, which were more severe and uniform in the ALA-PDT-treated area.

The study is paired and controlled, but the results should be evaluated with consideration given for the number of participating patients.

PDT appeared to be an effective treatment for inflammatory acne vulgaris with no significant differences in the response rate between ALA-PDT and MAL-PDT. ALA-PDT resulted in more prolonged and severe adverse effects after treatment.