Modified painless photodynamic therapy for facial multiple actinic keratosis in China: A prospective split-face control study

Background: Aminolevulinic acid photodynamic therapy (ALA-PDT) is an effective treatment for multiple actinic keratosis (AK). However, PDT-induced pain often discontinues the therapy to reduce its efficacy, limiting its application. If modified painless PDT schedule with shorter photosensitizer dressing and higher dose illumination could achieve good efficacy in AK, it is still unknown.Objectives: To explore the efficacy and pain tolerance of the modified painless PDT (M-PDT) in facial multiple AK.Methods: A split-face controlled clinical study including 14 patients with facial multiple AK was conducted. The patients received conventional PDT (C-PDT) on the left and M-PDT in the contralateral area. The left area (C-PDT) was illuminated by a red light-emitting diode light (144 J/cm(2)) after applying the 10% ALA cream for 3 h; the other had illumination for a total light dose of 288 J/cm(2) after applying the 10% ALA cream for 0.5 h. The primary endpoint was the lesion clearance rate at 1-month postthree sessions of PDT. Secondary endpoints included pain scores, the incidence of adverse events during treatment, and cosmetic outcomes.Results: At 1 month following three treatments, the total lesion clearance rate was comparable between M-PDT and C-PDT (91.6% vs. 89.0%). While the lesion clearance rate of M-PDT was higher than that of C-PDT in the Grade III lesions (86.5% vs. 72.0%, respectively) (p < 0.05). M-PDT achieved a 100% lesion clearance rate for Grade I lesions earlier than C-PDT, with M-PDT treated twice and C-PDT treated thrice. Moreover, the pain score during illumination was significantly lower for M-PDT than for C-PDT (p < 0.01). Regarding photoaging, the Global Subjective Skin Aging Assessment score showed that the total and atrophy scores of C-PDT and M-PDT were significantly improved, and M-PDT also reduced discoloration. There was no significant difference in adverse reactions between C-PDT and M-PDT.Conclusions: M-PDT is comparable to C-PDT's efficacy for treating facial multiple AK, resulting in much lower pain scores.