Trichoscopic findings of androgenetic alopecia and their association with disease severity.

Trichoscopy is a novel tool for the diagnosis of hair loss disorders such as androgenetic alopecia (AGA), but there are still few reports on the association between trichoscopic findings and disease severity, especially in the Chinese population. A case-control observational study was conducted to observe the trichoscopic findings of AGA and to evaluate their relationship with disease severity. Trichoscopic examination was performed with a handheld dermoscope on 750 Chinese male AGA (MAGA) and 200 female AGA (FAGA) patients, along with 100 male and 50 female normal controls. Trichoscopically, AGA was featured by hair shaft thickness heterogeneity (HSTH), brown peripilar sign (BPPS), white peripilar sign (WPPS), yellow dots, pinpoint white dots, focal atrichia and scalp pigmentation. No significant difference in the occipital area was found between AGA and controls (P > 0.05). HSTH of more than 20% was demonstrated in all MAGA patients, and HSTH of more than 10% was seen in all FAGA patients. WPPS, yellow dots, pinpoint white dots, focal atrichia and scalp pigmentation were positively related to severity of disease (P < 0.05), while BPPS was the contrary (P < 0.05). HSTH is an essential criterion for diagnosing AGA. BPPS was more common in early AGA. However, WPPS, yellow dots, pinpoint white dots, focal atrichia and scalp pigmentation are positively correlated with advanced AGA.