Abstract: MA Hui-jun, SONG Lian-jin, YANG Yang, HU Rong, ZHANG Ming-yue, GAO Peng-fei, WANG Jing-yi. Department of Dermatology, 309th Hospital of Chinese People′s Liberation Army, Beijing 100091, China Corresponding author: MA Hui-jun, Email: melanocytes@163.com 【Abstract】 Objective To evaluate the efficacy and safety of 308-nm monochromatic excimer light for the treatment of amelanotic nevus. Methods Eighteen patients with amelanotic nevus were treated with 308-nm monochromatic excimer light twice a week for five consecutive weeks. Melanin content index （MCI） was measured in the lesions before and after the treatment. After the final exposure, a three-month follow-up was carried out. Results After the start of treatment, the MCI in lesions increased in a session-dependent manner and approximated to 100% of that in perilesional normal skin after six sessions of treatment. The follow-up revealed a decrease trend in MCI after the end of the treatment, which was nearly equal to that in perilesional normal skin one month later, and dropped to about 90% of that three months later. No side effects such as blisters or scar were observed during the treatment. Conclusions The 308-nm monochromatic excimer light is safe and effective for the treatment of amelanotic nevus. Re-exposure to 308-nm monochromatic excimer light after three months is recommended as consolidation therapy.

Key words: Monochromatic excimer light