Photodynamic therapy (PDT) using daylight was as effective as PDT with an artificial light source in clearing grade I actinic keratoses (AKs) of the face and scalp after 3 months, but was associated with less pain and less severe side effects in a small Italian study.
The prospective intrapatient study compared the effects of DL-PDT with conventional PDT (c-PDT) at 3 months in 35 patients with multiple grade I AKs of the face and scalp in September and October 2013. Patients were treated with c-PDT on one side of the face and DL-PDT on the other side. For c-PDT, light therapy was administered after methyl aminolevulinate (MAL) cream was applied to the treatment area and occluded. For DL-PDT, MAL cream was applied to the treatment area, left uncovered for 30 minutes in the dark; patients then exposed these areas to daylight for 2 hours, between 11 a.m. and 3 p.m., after which the cream was wiped off.
At 3 months, the complete response rate of grade I AKs was 87% for DL-PDT and 91% for c-PDT, which was not a significant difference. It was less effective for grade II and III AKs in the study, though, and at 6 months, the recurrence rate for grade I AKs treated with DL-PDT was higher (17%) than for those treated with c-PDT (12%), with a P value less than .05.
Treatment with DL-PDT was associated with significantly less pain and less severe adverse events, with less erythema, crusting, and pustular eruption 2 days after treatment. In addition, 88% of the patients were more satisfied with DL-PDT, the authors said.
“Our study confirms that DL-PDT using MAL is an effective, safe, and convenient alternative for the treatment of grade I AKs ,” they concluded. “Interestingly, clinical response for AK I was significantly moderated by outdoor temperature, increasing at higher temperatures.”
The authors had no conflicts of interest. Dr. Fargnoli received a research grant from Galderma, Italy, but Galderma played no role in the study, according to the study’s disclosure statement. Galderma manufactures the MAL cream product used in the study.