Photodynamic therapy using intense pulsed light for treating actinic keratoses and photoaged skin of the dorsal hands: a randomized placebo-controlled study

Background The efficacy of photodynamic therapy (PDT) with intense pulsed light (IPL) has been shown for treating actinic keratoses (AK) and improving photoaged skin in the face but not yet on the dorsal hands. Objective To evaluate the efficacy of PDT with IPL for treating AK of the dorsal hands, inducing neocollagenesis, and improving photoaged skin. Methods In this prospective, randomized, placebo-controlled, monocentric, within-patient, observer-blinded trial, patients with 1 to 4 mild-to-moderate AK on the dorsal hands were randomly allocated to two different treatment groups: methyl aminolevulinate (MAL) and IPL (λ ≥600nm, 16.2 J/cm², 3 passes, Ellipse Flex PPT) (MAL-IPL) or placebo and IPL (λ ≥600nm, 16.2 J/cm², 3 passes, Ellipse Flex PPT) (placebo-IPL). Patients received three treatments in six-week intervals, and follow-up was 10 weeks after the last treatment. 37 patients aged 68.84±9.28 years were randomized. Primary study endpoints were complete AK clearance per hand and neocollagenesis of subepidermal collagen 10 weeks after the last treatment. Results Ten weeks after the last treatment, complete AK clearance rates per hand were 54.6% after MAL-IPL and 3.0% after placebo-IPL (p<.0001); complete AK clearance rates per lesion were 69.2% and 14.7% respectively (p<.0001). Thickness of the subepidermal collagen band had increased by 290.6% (±327.4%, p<.001) after MAL-IPL and by 215.5% (±215.3%, p<.001) after placebo-IPL without any significant difference between the two groups. Ratings regarding mottled pigmentation and overall appearance by the blinded investigator were significantly higher for MAL-IPL than for placebo-IPL. Wrinkle size (MAL-IPL: -24.4%, p=.003; placebo-IPL -23.1%, p=.004) and skin roughness (MAL-IPL: -19.6%, p<.001; placebo-IPL: -16.1%, p=.009) were significantly reduced in both groups without any significant difference between the two groups. Conclusions On the dorsal hands, MAL-IPL reduced AK more efficaciously than placebo-IPL; both treatment modalities significantly improved photoaged skin. This article is protected by copyright. All rights reserved.