18-year-old girl with circumscribed bald patch on scalp with no organic disease and behavioural disorder has

Trichotillomania(compulsive hair pulling) is characterised by noticeable hair loss caused by person's persistent and recurrent failure to resist an impulse to pull out hair. there is an intense urge to pull out hair without mounting tension before the act and a sense of relief afterwards. there is no pre-existant skin lesion or inflammation, and hair pulling is not secondary to delusion or hallucination. (Ref: a sho textbook of psychiatry, Niraj Ahuja, 7th edition, pg no.119)