Onychotillomania is a compulsive behavior in which a person picks constantly at the nails or tries to tear them off. It is not the same as onychophagia, where the nails are bitten or chewed, or dermatillomania, where skin is bitten or scratched. Onychotillomania can be categorized as a body-focused repetitive behavior in the DSM-5 and is a form of skin picking, also known as excoriation disorder.