Usually starts in childhood as a nervous habit.
Approximately 33% of children 7-10 years and 45% of adolescents aare nail biters.
Differential diagnosis includes psoriasis, onycholysis, lichen planus and trauma.
Complications include nail, cuticle, dental problems with bacterial infections and paronychia.
Exacerbated by physical inactivity.
May be associated with trichotillomania.
Considered by some as an impulse control disorder.
Many patients have anxiety disorders.