Trichodaganomania: the compulsive habit of biting one's own hair.

A 17-year-old male presented with patches of hair loss on both forearms with comorbid depression and anxiety disorders. He had irresistible urges to bite his hair on easily approachable sites and endorsed biting his hair during periods of severe anxiety and boredom, resulting in noticeable patches of hair loss. There was no evidence of trichotillomanic behavior or any other skin pathology resulting in loss of hair at those sites. Microscopy of the bitten end of hairs showed smooth, sharply demarcated, blunted shafts. Trichodaganomania (biting one's own hair) should not be confused with trichotillomania, trichotemnomania, or trichoteiromania. A psychodermatologic evaluation is warranted in the evaluation of these cases.