Abstract: Sun Zhenyan, Zhang Siping, Zhang Jing, Zhou Ao, Zheng Jianfeng Department of Dermatology, The People′s Hospital of Xuancheng City, Xuancheng 242000, Anhui, China （Sun ZY, Zhang J, Zhou A, Zheng JF）; Department of Dermatology, Anhui Provincial Hospital, Hefei 230001, China （Zhang SP） Corresponding author: Zhang Siping, Email: zsp3285@163.com 【Abstract】 Objective To analyze the dermoscopic features and patterns of onychomycosis. Methods From February to July in 2017, hospitalized patients from the Department of Endocrine Dermatology of the People′s Hospital of Xuancheng City was enrolled and subjected to direct microscopic examination of fungi in nails, and the patients with positive results for fungi were diagnosed with onychomycosis. And then, dermoscopic photographs of infected nails were taken to analyze the dermoscopic characteristics and patterns of onychomycosis. Results A total of 205 patients with 634 infected nails were investigated. The dermoscopic characteristics on the nail plates included marble-like turbid areas （47.3%, 300/634）, pigmentation （30.9%, 196/634）, splinter hemorrhages （18.3%, 116/634） and onycholysis （13.2%, 84/634）. The prevalence rates of marble-like turbid areas, pigmentation and onycholysis all significantly differed between distal and lateral subungual onychomycosis （DLSO） group and total dystrophic onychomycosis （TDO） group （χ2 = 42.09, 31.23, 18.19, respectively, all P < 0.01）. The dermoscopic characteristics at the free edge of the nails included nail thickening （33.1%, 210/634） and subungual deposition of keratin and debris （26.5%, 168/634）. The TDO group showed significantly higher prevalence rates of nail thickening and subungual deposition of keratin and detritus compared with the DLSO group （χ2 = 44.3, 18.52, respectively, both P < 0.01）. Periungual skin dryness and desquamation occurred more frequently in the TDO group than in the DLSO group （χ2 = 16.07, P < 0.01）. Of the 634 lesional nails, 141 （22.2%） showed a short spiked pattern, 210 （33.1%） showed a longitudinal striated pattern, 202 （31.9%） showed a linear edge pattern, and 193 （30.4%） showed a distal irregular termination pattern. Conclusion The main characteristic dermoscopic manifestations of onychomycosis are marble-like turbid areas, subungual deposition of keratin and debris, periungual skin dryness and desquamation, and characteristic dermoscopic patterns of onychomycosis are short spiked pattern, longitudinal striated pattern, linear edge pattern and distal irregular termination pattern.

Key words: Onychomycosis, Dermoscopy, Pattern analysis