Trichophagia

Trichophagia is a form of disordered eating in which persons with the disorder suck on, chew, swallow, or otherwise eat hair.^[1] The term is derived from ancient Greek θρίξ, thrix ("hair") and φαγεῖν, phagein ("to eat").^[2] Tricho-phagy refers only to the chewing of hair, whereas tricho-phagia is ingestion of hair, but many texts refer to both habits as just trichophagia.^[3] It is considered a chronic psychiatric disorder of impulse control.^[4] Trichophagia belongs to a subset of pica disorders and is often associated with trichotillomania, the compulsive pulling out of ones own hair.^[1] 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.^[5] In an even smaller subset of people with trichotillomania, their trichophagia can become so severe that they develop a hairball.^[6] 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.^[7]

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. ^[8]