MONDAY, Nov. 20, 2023 -- Modified 5-aminolevulinic acid photodynamic therapy (M-PDT) is effective for moderate-to-severe acne vulgaris and results in quicker responses than low-dose isotretinoin (ISO) therapy, according to a study published in the December issue of the Journal of the American Academy of Dermatology.

Linglin Zhang, M.D., from the Tongji University School of Medicine in Shanghai, and colleagues conducted a multicenter randomized clinical trial involving participants with moderate-to-severe acne vulgaris. A total of 152 participants were randomly assigned to M-PDT (up to five weekly sessions following manual comedone extraction) or ISO (0.5 mg/kg/day for six months) and were followed for up to six months after treatment.

The researchers found that the overall effective rates were significantly higher in the M-PDT group versus the ISO group at one month (67.74 versus 10.26 percent), but after one month, rates were higher in the ISO group (75.81 versus 97.44 percent). The time to achieve 50 percent lesion improvement was significantly lower in the M-PDT group than the ISO group (one versus eight weeks). Systemic side effects such as hepatotoxicity were experienced by 70.67 percent of patients in the ISO group, while side effects in the M-PDT group were skin-limited.

"Compared with low-dose ISO, M-PDT showed a rapid onset of effect with tolerable topical adverse effects and comparable outcomes at six months after therapy," the authors write.