Diagnostic Accuracy of Trichoscopy in Trichotillomania: A Systematic Review.

Trichotillomania is formally classified as a mental health disorder, but it is commonly diagnosed by dermatologists. The aim of this systematic review is to assess the diagnostic value of trichoscopy in diagnosing trichotillomania. The analysis identified the 7 most specific trichoscopic features in trichotillomania. These features had the following prevalence and specificity: trichoptilosis (57.5%; 73/127 and 97.5%, respectively), v-sign (50.4%; 63/125 and 99%), hook hairs (43.1%; 28/65 and 100%), flame hairs (37.1%; 52/140 and 96.5%), coiled hairs (36.8%; 46/125 and 99.6%), tulip hairs (36.4%; 28/77 and 89.6%), and hair powder (35.6%; 42/118 and 97.9%). The 2 most common, but least specific, features were broken hairs and black dots. In conclusion, trichoscopy is a reliable new diagnostic method for hair loss caused by hair pulling. Trichoscopy should be included as a standard procedure in the differential diagnosis of trichotillomania in clinical practice.