Abstract: Su Huichun*, Cheng Bo, Liu Jingjing, Wang Yuying. *Department of Dermatology, First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, China Corresponding author: Cheng Bo, Email: chengbo0415@126.com 【Abstract】 Objective To evaluate the efficacy and safety of an acne-clearing device in treating acne vulgaris. Methods A bicenter, randomized, single-blinded, placebo-controlled, parallel-group study was conducted. Seventy-three patients with mild to moderate acne vulgaris were enrolled for the trial. Two similar, clinically matched inflammatory papules were selected from each patient, and divided into a test group and a control group to be treated with an acne-clearing device with an output temperature of 46 － 50 ℃ and a control device without heat source respectively, for three sessions with the interval varying from 1 to 12 hours between the first two sessions and from 18 to 48 hours between the last two sessions. Every treatment lasted three minutes. Lesional color and size were recorded before and on day 1, 5 and 14 after the first treatment. Side effects were also recorded for the evaluation of safety. Results Clinical improvement was observed in 66 （90.4%）, 73 （100.0%） and 72 （98.6%） patients, and marked improvement in 27 （37.0%）, 64 （87.7%） and 72 （98.6%） patients on day 1, 5 and 14 after the first treatment, respectively. Significant differences existed between the control and test group in improvement rate on day 1 and 5, and in marked improvement rate on all the three time points （all P < 0.01）. The average time taken for erythematous swelling to begin to subside and time for lesions to completely heal were 19.51 hours and 7.15 days respectively in the test group, significantly shorter than those in the control group by 82.41 hours and 5.07 days respectively. Conclusions The acne-clearing device proves to be effective and safe for the treatment of mild to moderate acne vulgaris, which can rapidly relieve the inflammation in acne, shorten the time required for erythematous swelling to subside and for lesions to completely heal.

Key words: Acne vulgaris, Physical therapy modalities, Hyperthermia, induced, Randomized controlled trials