Dermoscopic features of androgenetic alopecia and their clinical implications

Abstract

Objective To investigate the dermoscopic features of androgenetic alopecia (AGA) and to assess their clinical implications.Methods A handheld dermoscope was used to observe the balding scalp of 200 male patients with AGA (MAGA),80 female patients with AGA (FAGA),as well as normal scalp of 50 human controls without hair loss.Clinical information was also collected from these subjects.Results Of the male and female AGA patients,100.0％ and 88.8％ showed hair diameter diversity (HDD) ＞ 20％ in the balding areas respectively,47.0％ and 41.3％ showed brown peripilar sign respectively,and 23.5％ and 17.5％ showed white peripilar sign respectively,35.0％ and 38.8％ showed scalp pigmentation respectively.Yellow dots were observed in 22.5％,31.3％ and 14.0％ of the male AGA patients,female AGA patients and controls respectively,pinpoint white dots in 24.0％,23.8％ and 18％ respectively,focal atrichia in 28.5％,67.5％ and 2.0％ respectively,and scaling in 49.0％,56.3％ and 50.0％ respectively.The incidence rate of HDD ＞ 20％ was significantly lower,but that of focal atrichia was significantly higher,in female AGA patients than in male AGA patients (both P ＜ 0.01).All the female patients with advanced AGA showed HDD ＞ 20％ with significant differences between female patients with AGA of grade F1 and those with AGA of grade F2-F3 (P ＜ 0.05),whereas white brown peripilar sign was mainly observed in male patients with early AGA with significant differences between male patients with AGA of grade Ⅱ-Ⅲ and those with AGA of grade Ⅳ-Ⅶ (P ＜ 0.05).The presence of white peripilar sign,scalp pigmentation and focal atrichia was positively correlated with the severity of AGA (all P ＜ 0.05).Conclusions Common dermoscopic findings in AGA include HDD ＞ 20％,brown peripilar sign,white peripilar sign,yellow dots,pinpoint white dots,focal atrichia,scalp pigmentation and scaling,among which,HDD ＞ 20％,brown peripilar sign and focal atrichia seem to be characteristics of AGA. Key words: Alopecia; Androgen; Dermoscopy