Photodynamic therapy of multiple actinic keratoses: reduced pain through use of visible light plus water-filtered infrared A compared with light from light-emitting diodes

Summary Background Photodynamic therapy (PDT) with methyl aminolaevulinate (MAL) is an effective treatment for multiple actinic keratoses (AKs). Pain, however, is a major side‐effect. Objectives To compare pain intensity, efficacy, safety and cosmetic outcome of MAL PDT with two different light sources in an investigator‐initiated, randomized, double‐blind study. Methods Eighty patients with multiple AKs grade I–II were assigned to two groups: group 1, MAL PDT with visible light and water‐filtered infrared A (VIS + wIRA); group 2, MAL PDT with light from light‐emitting diodes (LEDs), with a further division into two subgroups: A, no spray cooling; B, spray cooling on demand. MAL was applied 3 h before light treatment. Pain was assessed before, during and after PDT. Efficacy, side‐effects, cosmetic outcome and patient satisfaction were documented after 2 weeks and 3, 6 and 12 months. Where necessary, treatment was repeated after 3 months. Results Seventy‐six of the 80 patients receiving MAL PDT completed the study. Patient assessment showed high efficacy, very good cosmetic outcome and high patient satisfaction. The efficacy of treatment was better in the group of patients without spray cooling (P = 0·00022 at 3 months, P = 0·0068 at 6 months) and showed no significant differences between VIS + wIRA and LED. VIS + wIRA was significantly less painful than LED: the median of maximum pain was lower in the VIS + wIRA group than in the LED group for PDT without spray cooling. Pain duration and severity assessed retrospectively were less with VIS + wIRA than with LED, irrespective of cooling. Conclusions All treatments showed high efficacy with good cosmetic outcome and high patient satisfaction. Efficacy of treatment was better without spray cooling. VIS + wIRA PDT was less painful than LED PDT for PDT without spray cooling.