A 29-year-old patient with no medical history presented with hair loss on the thighs evolving for the last two years. Clinical examination revealed an irregular alopecic patch on the anterolateral thigh area (Fig. 1a) with a negative pull test. Dermoscopy revealed irregularly broken hairs, black dots, V-shaped hair, and trichoptilosis (Fig. 1b), consistently with the diagnosis of trichotillomania. He was treated with N-acetylcysteine and cognitive behavioral psychotherapy. Trichotillomania, also known as the hair-pulling disorder, is a mental disorder that involves recurrent, irresistible urges to pull out hair from the scalp, eyelashes, eyebrows, nose, or another part of the body, despite trying to stop. This leads to manifest alopecia on the affected parts of the body [1]. Trichoscopic criteria have been well described for trichotillomania of the scalp, including broken hair in different lengths, short hair with trichoptilosis, coiled hair, hook hair, tulip hair, flame hairs, and the V sign [2,3]. Trichotillomania may create a diagnostic challenge, especially if it occurs on a body site other than the scalp and/or if the patient denies the hair-pulling habit, therefore the importance of dermoscopy by demonstrating the specific trichoscopic patterns, allowing us to confirm the diagnosis without resorting to histology.

Figure 1: (a) Hair loss on the anterolateral thigh area. (b) Dermoscopic features of trichotillomania, irregularly broken hairs (yellow arrow), black dots (blue arrow), and V hairs (green arrow).

REFERENCE

1. Martin JM, Montesinos E, Cordero P, Gonzalez V, Ramon D. Trichoscopic features of trichotillomania. Pediatr Dermatol. 2019;36:265-7.

2. Karrakchou B, Fliti A, Hamich S, Ismaili N, Benzekri L, Meziane M, et al. Acquired non-scarring vertex alopecia in three women revealing trichotillomania:Diagnostic accuracy of trichoscopy. Our Dermatol Online. 2023;14:228-9.

3. Malakar S, Mukherjee SS. 'Mace sign’- A defi nitive sign of trichotillomania?. Our Dermatol Online. 2017;8:491-2.