Photodynamic therapy (PDT) is an efficacious treatment for acne and a good adjunctive treatment for mild to severe acne, especially in patients who have not responded to topical therapy and oral antibacterials, and are not great candidates for isotretinoin, according to a recent review. Researchers performed a systematic literature review and critically evaluated the studies. 69 clinical trials, 4 case reports, and 2 retrospective studies met the inclusion criteria, and 7 of the studies were high quality. They concluded:

• The most common photosensitizers used were 5-aminolevulinic acid and methyl aminolevulinate, and both showed similar response.
• Red light was the most frequently used light source, followed by intense pulsed light, and showed comparable results.
• Inflammatory and non-inflammatory lesions both responded to treatment, with inflammatory lesions showing greater clearance in most studies.
• Adverse events associated with PDT for acne were mild and included pain on illumination and post-procedural erythema and edema.