Onychophagia or nail biting

What is onychophagia ?

Onychophagia is the habit of compulsive nail biting.

Nail biting is the commonest, tic or compulsive habit among Europeans. Our study shows that onychophagia is both a psychological and physical manifestation that can be considered to be an addiction.

Probable causes of nail biting and the beginning of an explanation.

Like other addictions, nail biting gives the individual a feeling of peace and reduces nervous tension in stressful situations. The causes may be varied, ranging from transient stress to a state of advanced and long-lasting anxiety. Boredom or feelings of personal discomfort, both physical and psychological, can lead the subject to nail biting.

The causes are many and varied, and may go back a long way to early childhood. We can meet many examples in our daily lives.

This shows us that nail biting is not a trivial matter, but is instead the physical representation of an intense psychological battle.

Occasionally nail biting can be a sign of genuine self-aggression or self-punishment.

According to data from several psycho-sociological studies, nail biting begins at an early age regardless of sex.

Different authors describe the nail-biting subject as a sensitive person, often nervous, who has difficulty in expressing their feelings. The nail biter may have a form of withdrawal, indifference or apparent distraction with respect to their surroundings. Conversely they can be extremely angry, stubborn and tenacious in the face of situations that affect their lives. Their behaviour may also include some form of denial, disobedience or difficulty to listen and memorize instructions.

Nail biting, a social phenomenon

We live in a society of Beauty and Aesthetics where everything goes faster and where the demands of results and success increasingly push us to the extreme. We expect most of our children to compete in school from a very early age.

The conscientious child can focus the pressure felt on the tips of their fingers.

The idea is that the established elegantly manicured hand is one of the unique aspects of femininity and success for a woman. The idea is especially promulgated among young girls on whom this model is imposed. This notion of social success associated with beautiful hands is also true for men but to a lesser extent. This explains why women are prepared to try harder than men to recover and lose the bad habit of nail biting.


From a medical point of view, hands are the vectors of countless germs. Even if the person washes their hands regularly there will always be some bacteria, viruses and parasites under the fingernails at the edge of the fingers. Onychophagia can therefore be the cause of multiple infections. The most common are those affecting the gastrointestinal area, resulting in diarrhoea, nausea and vomiting.

Nail biting facilitates the spread of many infectious diseases such as bacterial or fungal aphtha like candidiasis. Herpes is the most common viral disease linked to nail biting. The subject who bites their nails facilitates the spread of herpes virus not only around the mouth, but also spreads contamination around their fingers.

Onychophagia can create wounds that favour the formation of a paronychia. Paronychia is an acute infection of the finger at the junction of the nail and skin. The finger becomes red, inflamed and painful and filled with pus, a sign of infection. Untreated paronychia may lead to the formation of an abscess.

Treatment and prevention

Most specialists agree that the treatment of nail biting is restrictive: bitter polish on the nails, self-admonitions or reprimands from family members, self-control, suggestion and auto-suggestion, dressings on the fingertips.

The bitter nail polish is about the only "physical" treatment for onychophagia. Given that onychophagia is primarily a psychological disease, other treatments are mostly psychological. A method of "reversal of habits" was developed by Azrin and Nunn in 1973, and is easily accessible on the Internet. Encouragement and congratulations from those around the sufferers from, family, friends, and colleagues plays an important role. This allows the subject to gain confidence, to progress more rapidly, and eventually control his ICD (Impulsive Compulsive Disorder).

If made with a natural extract, a bitter varnish is completely harmless to the body, even if ingested. It can easily discourage young people starting this compulsive habit. However, the bitter varnish alone cannot constitute an effective and appropriate solution to an individual marked with a severe and refractory onychophagia. In this case the use of the bitter varnish will be in addition to an appropriate psychological treatment.

In summary the bitter varnish is an adequate treatment for minor cases as well as in more-established cases. In the latter case it is always in addition to a psychological treatment. One should not forget that stopping onychophagia is mainly due to the motivation of the subject and their awareness of their condition.

In conclusion

Onychophagia is a disease that takes a physical form from a psychological cause. The issue is linked to the person as a whole: their personal history, their character, and therefore any treatment has to be adapted on a case by case basis.

If onychophagia persists despite different treatments and care, the psychological approach by a health professional is the safest way to respond effectively to this compulsive disorder.

Abstract of a synthesis for Aclae Santé
by Benjamin Steele,
Junior Association Studies
Faculty of Pharmacy 11 South Paris, Chatenay-Malabry. France.