OVERVIEW

What is onychophagia?

Onychophagia, commonly known as nail-biting, is a habitual behavior of repeatedly biting fingernails, and sometimes toenails. It is a compulsive, often unconscious or difficult-to-control habit that typically occurs during times of stress, anxiety, boredom, or hunger.

Onychophagia may be a temporary, relatively mild behavior, but it can also develop into a severe and long-term issue, such as psychological problems.

This habit usually begins in childhood, becomes most noticeable and severe during adolescence, and may persist into adulthood. However, as individuals grow older, the habit often gradually diminishes or stops.

Additionally, individuals with onychophagia may feel shame, guilt, or emotional distress due to the condition, making support and encouragement from parents and those around them particularly important.

Is onychophagia a mental illness?

Onychophagia is broadly classified as a mental disorder.

Currently, onychophagia is considered a body-focused repetitive behavior (BFRB). The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Psychiatric Association, categorizes onychophagia under "Other Specified Obsessive-Compulsive and Related Disorders."

Is onychophagia the same as nail-biting?

Yes, the two terms are equivalent. "Nail-biting" is the colloquial term, while "onychophagia" is the formal, written term.

SYMPTOMS

What are the symptoms of nail-biting habit?

The severity varies, but generally, it only involves abnormal manifestations of the nails and surrounding skin.

Possible symptoms include uneven nail edges, loose attachment between the nail and surrounding skin, bleeding, hangnails, or pain in the skin around the nails. In some cases, it may lead to complete nail loss or significant deformation.

Additionally, nail-biting may coexist with other mental health issues, such as attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder, separation anxiety disorder, enuresis, or obsessive-compulsive disorder.

Other body-focused repetitive behaviors may also occur, such as hair-pulling (trichotillomania), skin-picking (dermatillomania), or nail-picking (onychotillomania).

Beyond physical appearance and behavior, nail-biting often has psychological manifestations, such as tension before biting, relief or pleasure afterward, as well as shame, embarrassment, or guilt, typically related to damaged skin/nails.

What are the harms of nail-biting?

Nail-biting can sometimes affect quality of life. Socially, it may damage nail appearance, leading to low self-esteem, distress, and impaired social functioning.

In severe cases, nail-biting can harm physical health, potentially causing small cracks in the front teeth, gingivitis, or gum abscesses.

It may also lead to various infections: bacterial infections like paronychia, viral infections such as periungual warts or herpetic whitlow, and fungal infections like onychomycosis.

CAUSES

Is nail biting caused by a deficiency of calcium, iron, zinc, selenium, or vitamins?

No. Nail biting has no relationship with nutritional factors such as vitamins or minerals.

What are the causes of nail biting?

Nail biting is often a spontaneous, unconscious abnormal behavior. Its underlying causes remain debated and may be related to genetics (heredity), psychological factors, acquired habits, and family influences.

One theory suggests that nail biting is a continuation of thumb-sucking habits.

Many also believe that nail biting may be a coping mechanism when facing difficulties or stress. Low self-esteem or lack of stimulation (e.g., boredom) can trigger or worsen nail biting. Chewing nails may help relieve stress, tension, or boredom.

Additionally, genetics may play a role. On one hand, children of parents who bite their nails are more likely to develop the habit. On the other hand, some people have a genetic predisposition to develop repetitive body-focused behaviors, and their immediate family members may exhibit higher-than-average rates of mood and anxiety disorders.

Is nail biting hereditary?

It may be hereditary, but there is no definitive conclusion yet. Some believe that children of parents who bite their nails are more likely to do so, but the likelihood is not significant enough to warrant excessive concern.

DIAGNOSIS

How is Onychophagia Diagnosed?

It is primarily diagnosed by a medical professional based on the following criteria: a long-term nail-biting habit, observable physical manifestations caused by nail-biting, the behavior being spontaneous/unconscious, and inquiries into related conditions (including psychological factors).

TREATMENT

How to Treat Nail Biting?

Nail biting often resolves on its own, so mild or infrequent cases may not cause significant negative effects and may not require special treatment. If treatment is necessary, a plan should be developed with a professional doctor, and the child or adult with the habit must actively cooperate and attend regular follow-ups.

Scolding, teasing, punishing, or stopping a child from biting their nails is usually ineffective. Traditional methods like applying bitter-tasting substances to the nails also tend to fail, as they may increase anxiety.

Barrier interventions that prevent oral contact with the nails, such as gloves, socks, fixed devices, or bite guards, can offer some protection and serve as reminders.

Other potentially helpful strategies include keeping nails neatly trimmed, chewing gum as a substitute, or keeping hands occupied with other activities to divert attention.

Certain medications can also be used to treat some cases of nail biting. Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed due to their moderate effectiveness and high safety profile.

Cognitive behavioral therapy (CBT) may be effective for some individuals, including techniques like habit reversal training, progressive muscle relaxation, and acceptance and commitment therapy. Habit reversal training is currently the most widely used approach.

In severe cases, treatment must also focus on reducing or eliminating emotional factors related to nail biting, such as anxiety or depression. If other mental health issues are present, a professional evaluation and management by a doctor are necessary.

Can Nail Biting Be Cured?

Many treatment options are available, but individual responses vary.

Can Nail Biting Be Overcome with Willpower?

It is possible but not guaranteed. Mild cases may be managed with willpower if the individual has sufficient self-awareness of their psychological and behavioral patterns.

Can Nail Biting Be Treated with Manicures or Essential Oils?

These methods are generally ineffective and may increase anxiety. Additionally, ingesting manicure products or essential oils like menthol poses health risks.

Why Are Antidepressants Used to Treat Nail Biting?

Selective serotonin reuptake inhibitors (SSRIs), a newer class of antidepressants, can be tried for nail biting. Their effects extend beyond depression and include treating anxiety disorders, obsessive-compulsive disorder (OCD), and anorexia nervosa.

The mechanism may involve serotonin, an important neurotransmitter that plays a key role in regulating mood.

DIET & LIFESTYLE

What should nail biters pay attention to in daily life?

Adjust emotions and behaviors to maintain normal quality of life. If improvement is not achieved, seek professional medical assistance for joint control of nail-biting. No dietary restrictions or additional nutritional supplements are required.

How does nail-biting affect life?

Nail-biting may sometimes impact quality of life. It damages nail appearance, potentially causing low self-esteem, distress, impaired social functioning, and occasionally strained family relationships.

PREVENTION

How to effectively prevent nail biting?

There are no effective preventive measures.