Objective To evaluate the diagnostic value of dermoscopy and reflectance confocal microscopy (RCM) alone or in combination for melanocytic nevus.Methods A total of 37 patients with clinically diagnosed melanocytic nevus were collected.Skin lesions were firstly examined by dermoscopy and RCM,then were resected to be subjected to histopathological examination for final diagnosis.The imaging features of melanocytic nevus were summarized.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of different skin imaging techniques were calculated,and the consistency was analyzed between skin imaging techniques and histopathological examination.Results Based on the dermoscopic and RCM findings,2 kinds of nevus cells with different morphological features were observed in the dermis of intradermal nevus.One kind of nevus cells was characterized by a nonfusional,highly-refractive round structure in the papillary dermis under RCM,and by a brown or light brown homogenous pattern under dermoscopy,which was observed in 5 skin lesions.The other kind of nevus cells appeared as irregular,highly-refractive cell clumps in the papillary dermis under RCM,and by a cobblestone or globular pattern under dermoscopy,which was observed in 31 skin lesions.For the diagnosis of melanocytic nevus,the sensitivity,specificity,accuracy,positive predictive value and negative predictive value of RCM combined with dermoscopy were 91.7％,87.5％,90.9％,97.1％ and 70％ respectively,those of RCM were 86.1％,75％,84％,93.9％ and 54.5％ respectively,and those of dermoscopy were 77.8％,87.5％,75％,96.3％ and 41.2％ respectively.All the diagnostic indices of RCM combined with dermoscopy were higher than those of RCM or dermoscopy alone,except that the specificity was equal to that of dermoscopy alone.RCM showed higher sensitivity,accuracy and negative predictive value,but lower specificity and positive predictive value compared with dermoscopy.There were no significant differences in the diagnostic yield in melanocytic nevus between RCM combined with dermoscopy or RCM alone and histopathological examination (x2 =0.25,0.57,P =0.63,0.45,Kappa value =0.72,0.53,respectively).However,a significant difference in the diagnostic yield in melanocytic nevus was observed between dermoscopy and histopathological examination (x2 =5.81,P =0.012).Conclusion RCM combined with dermoscopy shows higher diagnostic accuracy for melanocytic nevus compared with RCM or dermoscopy alone.

Objective To analyze correlations of the distribution of non-segmental vitiligo lesions with gender,age of onset,duration of disease,personal and family history of autoimmune diseases,family history of vitiligo,and so on.Methods Clinical data were collected from 1 125 patients with confirmed nonsegmental vitiligo in Department of Dermatology,Beijing Hospital from January 2009 to January 2019,and analyzed retrospectively.Statistical analysis was carried out with SPSS 20.0 software by using independentsample t test and chi-square test.Results Of the 1 125 patients with non-segmental vitiligo,599 were males and 526 were females,with a male-to-female ratio of 1.14:1.Their age of onset was 27.9 ± 17.1 years,and duration of disease was 5.2 ± 8.0 years.Skin lesions mostly occurred on the trunk (544 cases,48.4％) and face (535 cases,47.6％),followed by acral regions (430 cases,38.2％),extremities (297 cases,26.4％) and neck (231 cases,20.5％).The perioral region (17.2％),hands (47.9％) and genital region (14.5％) in the 599 male patients were more frequently affected than those in the 526 females (9.7％,22.6％,6.3％,x2 =13.33,77.66,20.01,respectively,all P ＜ 0.001),while the neck (27.0％) was more frequently affected in the female patients than in the male patients (14.9％,x2 =25.29,P ＜ 0.001).The age of onset was significantly lower in the patients with vitiligo lesions involving the legs,knees,feet,trunk,genital and periocular regions than in those without skin lesions on the above corresponding body sites (all P ＜ 0.05),but significantly higher in the patients with vitiligo lesions involving the arms and hands than in those without lesions on the above 2 sites (both P ＜ 0.05).Vitiligo lesions more likely occurred on the hands of patients with a personal or family history of autoimmune thyroid diseases compared with those without the personal or family history (50.0％ vs.27.9％,x2 =6.62,P =0.010).The trunk was more frequently affected in the patients with a family history of vitiligo than in those without (59.6％ vs.45.7％,x2 =13.36,P ＜ 0.001).Conclusion The distribution of non-segmental vitiligo lesions are correlated to some extent with gender,age of onset,personal and family history of autoimmune diseases and family history of vitiligo.