Abstract: 【Abstract】 Objective To analyze the dermoscopic and reflectance confocal microscopic characteristics of erythema dyschromicum perstans （EDP）, and to explore the value of dermoscopy and reflectance confocal microscopy （RCM） in the auxiliary diagnosis of EDP. Methods Clinical data were retrospectively collected from 5 patients with EDP, who visited and were treated in the Department of Dermatology, Hangzhou Third People's Hospital from January to December 2020. Three typical lesions were chosen from each patient, and the 15 lesions were examined by dermoscopy and RCM. Skin specimens were taken from 2 cases at the observation sites for histopathological examination. Results Among the 5 EDP patients, there were 3 males and 2 females, with an average age of 40.8 years （range, 24 - 62 years） and an average disease course of 15.7 months （range, 3 - 48 months）. Greyish-green patches extended to the trunk were observed in 3 cases, 1 case presented with lesions located on the bilateral upper limbs, and 1 presented with a solitary lesion on the neck. Dermoscopy showed that all 15 lesions exhibited a black pepper-like structure. RCM revealed focal liquefaction degeneration of basal cells in all 15 lesions. Histopathological examination of 2 cases showed focal liquefaction degeneration of basal cells and scattered pigmentophages in the dermal papilla. Conclusion EDP has typical dermoscopic and RCM characteristics, which could provide a basis for its diagnosis and differential diagnosis.

Key words: Pigmentation disorders, Dermoscopy, Microscopy, confocal, Erythema dyschromicum perstans, Ashy dermatosis