[Clinical-pathological analysis of 71 cases of dermatosis papulosa nigra of Han Chinese people].

Objective: To analyze and summarize the clinical-pathological features of dermatosis papulosa nigra of Han Chinese people. Methods: We collected 71 cases of dermatosis papulosa nigra in the Third people's Hospital of Hangzhou Affiliated to Zhejiang Chinese Medical University of Department of Dermatology from January 2010 to January 2019 which were confirmed clinically and pathologically. The clinical and histopathological data of all patients were analyzed and summarized, and relevant literature were reviewed. Results: Among the 71 patients, 51 were female and 25 were male, their average age was (44±13) years, the average age of onset was (39±14) years, and the average time of diagnosis was (65±51) months. The lesions were multiple dark brown papules with smooth surface, and mostly distributed in the chest and abdomen, 46 cases (64.8%), followed by the back and neck. The mean diameter of the lesions was (1.76±0.99) mm. Meanwhile, the initial onset of pruritus was observed in 15 patients. The pathological features of all lesions were similar to seborrheic keratosis. According to pathological classification, there were 49 (69.0%) cases of the acanthotic type, 11(15.5%) cases of the hyperkeratotic type, 6 (8.5%) cases of spiroid type, 4 (5.6%) cases of irritated type, and 1 (1.4%) case of clonal type. Epidermal pigmentation and/or dermal papillary pigmented granules were observed in 56 cases (78.9%), of which 46 cases (64.8%) had basal layer pigmentation. In addition, inflammatory cell infiltration was found in the superficial dermis of lesions of 10 patients (14.1%) with symptom of itching. Conclusion: Dermatosis papulosa nigra of Han Chinese people has some unique clinical and pathological features.