Intense Pulsed-light Therapy Significantly Improves Keratosis Pilaris: A Randomized, Double-blind, Sham...

Background: Keratosis pilaris (KP) is a common benign follicular disorder for which various topical and laser treatments have been used, with limited efficacy. Objective: We evaluated the efficacy of intense pulsed light (IPL) therapy for the reduction of skin roughness, erythema, and hyperpigmentation in Thai subjects with KP. Material and Methods: Twenty-four Thai patients with untreated KP on the upper outer arms were enrolled in a randomized, double-blind study. Only one arm of each subject was included and divided into upper and lower parts (25 cm² per each part). One part was randomized to be treated with IPL using 645 to 950-nm cutoff filter and fluences of 15 to 18 J/cm², while the other part was treated with sham irradiation. Subjects received four consecutive treatments at four-week intervals. Antera3D was used to measure skin roughness, erythema, and hyperpigmentation at baseline and four weeks after the last treatment. Moreover, clinical outcomes were also evaluated by subject Global Improvement Scores (GIS) and subject satisfaction grading scores. Results: Twenty-three subjects completed the study. There was statistically significant reduction of skin roughness, measured by Antera3D, compared to control group (p<0.001). However, the reduction of skin erythema was not significantly different between two groups (p=0.660). Skin hyperpigmentation significantly increased in the control group compared with intervention group (p=0.01). There were statistically significant improvements in skin roughness, erythema, hyperpigmentation, and overall appearance, graded by subject Global Improvement Scores (p<0.001). Subject satisfaction scores were significantly better in treatment parts (p<0.001). No adverse events, including burning, bulla, erosion, postinflammatory hyper/hypopigmentation, and scar formation developed in any subjects throughout study period. Conclusion: IPL has demonstrated the ability to significantly and safely reduce skin roughness in subjects with KP compared to control after four sessions.