ABSTRACT
Objective To evaluate the application value of polarized light dermoscopy in the diagnosis of vitiligo and differential diagnosis between vitiligo and other common hypopigmented diseases.Methods Dermoscopic images of lesions of 235 patients with confirmed vitiligo (130 with active vitiligo and 105 with stable vitiligo) were collected from the database in the Department of Dermatology,Xijing Hospital from January 2018 to July 2018,and retrospectively analyzed.Meanwhile,dermoscopic images of amelanotic nevus (151 cases),pityriasis alba (113 cases) and idiopathic guttate hypomelanosis (54 cases) were compared with the dermoscopic images of vitiligo.Chi-square test was used for comparison of rates among groups.Results The prevalence of perifollicular pigmentation,reticular pigmentation,starburst,Tapioca sago and micro-Koebner phenomenon was significantly higher in the patients with active vitiligo than in those with stable vitiligo (x2 =36.5,151.2,13.0,14.9,8.4 respectively,all P ＜ 0.05).The prevalence of perifollicular pigmentation,perilesional hyperpigmentation,perifollicular telangiectasia,leukotrichia was significantly higher in patients with stable vitiligo than in those with active vitiligo (x2 =91.2,166.0,54.3,41.1 respectively,all P ＜ 0.05).The prevalence of residual perifollicular pigmentation was significantly higher in patients with active (89.2％,116/130) or stable vitiligo (54.3％,57/105) than in those with amelanotic nevus (20.5％,31/151,P ＜ 0.05),pityriasis alba (12.4％,15/113,P ＜ 0.05)or idiopathic guttate hypomelanosis (9.3％,5/54,P ＜ 0.05).Conclusion Residual perifollicular pigmentation could serve as an important feature for distinguishing vitiligo from achromic nevus,pityriasis alba and idiopathic guttate hypomelanosis,and polarized light dermoscopy shows good value in the differential diagnosis between vitiligo and some hypopigmented diseases.