Onychophagia

Onychophagia

Onychophagia (pronounced on‑i‑ko‑FAY‑jee‑ah) is the medical term for chronic morderse las uñas — a body‑focused repetitive behaviour (BFRB) that involves chewing the fingernails, toenails, and sometimes the surrounding skin. While occasional nail biting is common and often harmless, onychophagia refers to a persistent habit that can lead to physical damage and emotional distress.

How Onychophagia Is Classified

• Medical Category: Impulse control disorder / BFRB
• Related Conditions: Onychotillomania (compulsive nail picking), dermatophagia (skin biting), trichotillomania (hair pulling)
• Diagnostic Context: Recognised in the Diagnostic and Statistical Manual of Mental Disorders (DSM‑5) under Other Specified Obsessive–Compulsive and Related Disorders

Causes and Triggers of Onychophagia (Chronic Nail Biting)

Onychophagia can develop at any age but often begins in childhood.
Common contributing factors include:

• Psychological triggers: Stress, anxiety, boredom, or perfectionism
• Learned behaviour: Observing morderse las uñas in parents, siblings, or peers
• Neurodevelopmental links: Higher prevalence in individuals with ADHD, OCD, or anxiety disorders
• Sensory reinforcement: The physical sensation of biting may provide temporary comfort or relief

Health Risks and Complications of Onychophagia

Persistent onychophagia can result in:

• Placa ungueal deformation and slowed growth
• Damage to cuticles and periungual skin
• Painful padrastros y inflamación
• Increased risk of bacterial, viral, or infecciones fúngicas
• Dental damage including chipped teeth and enamel wear
• Transfer of patógenos from fingers to mouth, potentially causing illness

Management and Treatment

Breaking the cycle of onychophagia often requires a combination of strategies:

• Behavioural interventions: Habit Reversal Training (HRT) and stimulus control
• Stress management: Mindfulness, relaxation exercises, or therapy to address underlying anxiety
• Physical deterrents: Bitter‑tasting recubrimientos de uñas, gloves, or adhesivo nail covers
• Profesional cuidado de las uñas: Regular manicures to protect nails and encourage maintenance
• Medical or psychological support: For severe or compulsive cases, referral to a GP, dermatólogo, or mental health professional

Prognosis

With consistent management, most people can significantly reduce or eliminate the habit. However, relapse is common, especially during periods of stress. Ongoing self‑monitoring and maintenance strategies are recommended.

See also:

• Morderse las uñas
• Onychotillomania