trichophagia

Trichophagia is a form of disordered eating in which persons with the disorder suck on, chew, swallow, or otherwise eat hair. The term is derived from ancient Greek θρίξ, ("hair") and φαγεῖν, ("to eat"). Tricho- refers only to the chewing of hair, whereas tricho- is ingestion of hair, but many texts refer to both habits as just trichophagia. It is considered a chronic psychiatric disorder of impulse control. Trichophagia belongs to a subset of pica disorders and is often associated with trichotillomania, the compulsive pulling out of ones own hair. People with trichotillomania often also have trichophagia, with estimates ranging from 48-58% having an oral habit such as biting or chewing (i.e. trichophagy), and 4-20% actually swallowing and ingesting their hair (true trichophagia). Extreme cases have been reported in which patients consume hair found in the surrounding environment, including other people's and animals' hair. In an even smaller subset of people with trichotillomania, their trichophagia can become so severe that they develop a hairball. Termed a trichobezoar, these masses can be benign, or cause significant health concerns and require emergency surgery to remove them. Rapunzel syndrome is a further complication whereby the hairball extends past the stomach and can cause blockages of gastrointestinal system.

Trichophagia occurs instinctively in many animal species and is not always a sign of a psychological disorder. Cats practice trichophagia as a form of regular grooming.