onychophagia

Onychophagia is the habit of biting, chewing, or otherwise gnawing one’s nails and surrounding cuticles. It is a common body-focused repetitive behavior, most often beginning in childhood. Prevalence estimates in children range widely, commonly cited around 20 to 30 percent, with many individuals outgrowing the habit in adolescence; persistent cases into adulthood occur but are less common.

Causes and associations: The behavior is influenced by stress, anxiety, boredom, or as a cue in routines; it can be part of broader obsessive‑compulsive spectrum disorders or body-focused repetitive behaviors (BFRBs). It may co-occur with other conditions such as attention‑deficit/hyperactivity disorder or autism spectrum disorder.

Complications and diagnosis: Recurrent nail biting can cause nail bed injuries, paronychia, infections, deformed nails, and dental wear. Diagnosis is clinical, based on observation and history; there are no formal criteria separate from the broader category of BFRBs.

Management and prognosis: Treatment aims to reduce frequency and address underlying factors. Behavioral approaches such as habit reversal training (awareness of episodes, competing response) and cognitive‑behavioral therapy are commonly used. Other strategies include stress management, varnishes with bitter taste, nail trimming, hand barriers, and replacing the habit with fidget tools. Pharmacotherapy is not routinely indicated but may be considered if there is significant underlying anxiety or OCD symptoms. The prognosis is variable; many children outgrow it, while some individuals require ongoing management to prevent relapse.