Causes, Treatments, and Signs of Dermatophagia

People with dermatophagia generally bite the skin around the fingernails and cuticles. Others may bite the skin on their knuckles, the nail folds, the inside of their cheek, or their lip. Some people chew their tongue or bite their hangnails. It can be a conscious or subconscious habit. Although the individual bites the skin, they do not usually consume it, which is why some physicians and researchers prefer the term “dermatodaxia” as a more accurate description.

If the condition worsens to the point where there is bleeding, scarring, or thickened skin in the chewed-on areas, the doctor may suspect that the behavior has become a type of pathological skin picking (PSP). This is a body-focused repetitive behavior (BFRB). The American Psychiatric Association diagnostic handbook lists BFRBs under obsessive-compulsive and related disorders. However, not everyone with dermatophagia has obsessive-compulsive disorder (OCD).

Bleeding or scarring of the fingers, cuticles, and skin around the nails are common signs of the condition. An individual who chews on oral tissues like the cheek or lips may develop keratoses — callus-like patches. Physical damage indicates that the behavior has become habitual. Without treatment, the areas can become infected. Some individuals experience a reactive thickening of the skin instead of a wound, loss of skin, or ulceration.

Like other obsessive compulsive-related disorders, dermatophagia often occurs alongside anxiety and depression. Once the person bites their skin, they feel relief for some amount of time before feeling anxious again. Some research indicates that dermatophagia could be a form of self-injurious behavior, but many mental health practitioners disagree.

People with dermatophagia may also exhibit signs of excoriation disorder, an uncontrollable, repetitive picking and rubbing of the skin. Excoriation disorder affects between 1.4% and 5.4% of the general population to the extent of noticeable tissue damage. Nail biting, or onychophagia, is another type of BFRB that may accompany dermatophagia. Studies indicate that BFRB behaviors like dermatophagia are a form of self-soothing.

The reasons why people develop dermatophagia are unknown, but mental health experts agree that it is not usually a sign of underlying trauma or a deep-seated, psychological problem. People exhibiting these and similar behaviors usually have the intent to improve or correct perceived body imperfections, but they seldom intend to self-harm. They may also engage in the behavior to reduce boredom.

Studies indicate a possible biological link between dermatophagia and other BFRB behaviors, especially among immediate family members. Most of the time, people with dermatophagia are unaware of their behavior. A few studies suggest that people with dermatophagia are more likely to have attention-deficit/hyperactivity disorder (ADHD) or a genetic marker for OCD. However, researchers say more studies are necessary to determine any connections.

Physicians do not always recognize the symptoms of dermatophagia. It is a relatively new mental health concept, so some physicians may fail to consider it as a possible diagnosis. To warrant a diagnosis, dermatophagia must cause distress or interfere with the individual’s ability for daily functioning. Symptoms must not be the result of another psychiatric or medical disorder or a side effect of medications.

Dermatophagia is not a bad habit that a person can “break.” Each type of BFRB is unique and the treatment process is often complex. Self-tracking and awareness of the behavior along with the identification of triggers and patterns can be effective. Behavioral experts suggest habit reversal training to replace skin-biting behaviors. Cognitive behavioral therapy and dialectical behavioral therapy may also be helpful.

People who are unable to stop skin biting often feel shame due to the lack of control over the behavior, especially if there are physical signs. They may self-isolate and withdraw from social interactions. Peer support groups may help individuals make connections with those who have similar issues. Therapy can help with managing the behaviors, limiting their effect on day-to-day life.