Trichotillomania

Trichotillomania is a body-focused repetitive behaviour disorder in which the person pulls out their own hair. It is classified in DSM-5 as an obsessive-compulsive and related disorder.

Clinical picture: irregular patches of hair loss in distributions accessible to the person’s hands (most commonly scalp, eyebrows, eyelashes). Hairs within the patch are of varying lengths, including very short hairs that have grown back since the last pulling episode. This contrasts with alopecia areata, which produces sharp-bordered patches of complete loss.

Trichoscopy shows broken hairs at varying lengths, “flame hairs” (residue of forcefully removed hair), and irregular patch borders. A skilled dermatologist can usually distinguish trichotillomania from alopecia areata clinically.

Treatment is behavioural rather than dermatological. Habit reversal training (a form of cognitive behavioural therapy) has the strongest evidence. Some patients benefit from N-acetylcysteine, SSRIs, or atypical antipsychotics, prescribed and monitored by mental health clinicians.

The hair regrows fully in most cases when the pulling stops. Extended chronic pulling can cause scarring with permanent loss in some cases.