The habit of biting, picking, and subsequently consuming small pieces of one’s own skin is more common than many people realize. This behavior often involves the skin around the fingers, such as cuticles, or the lips.
While it may seem like a simple nervous habit, the repeated ingestion of skin tissue can raise questions about biological consequences.
This discussion focuses on the physiological journey of the consumed material and the physical and psychological risks associated with the behavior.
The Digestive Journey of Keratin
The primary component of the outermost layer of human skin is a tough, fibrous structural protein called alpha-keratin. This protein provides the skin with its strength and protective qualities, making it highly resistant to breakdown. When small bits of skin are swallowed, they enter the digestive tract where the body attempts to process them.
The human digestive system lacks the specialized enzymes necessary to fully cleave the strong disulfide bonds that link the keratin proteins together. Consequently, the ingested material is not broken down into usable amino acids for absorption.
Instead of being digested, the small pieces of keratinized tissue typically pass through the entire gastrointestinal tract undigested. For most people engaging in this habit, the small quantities consumed do not pose an immediate digestive obstacle.
Health Risks from Ingested Skin
A significant physical risk associated with eating one’s skin comes from the transfer of microorganisms into the digestive system. The surface of the skin, especially under the nails and around the cuticles, harbors a variety of bacteria, some of which are potentially harmful. Introducing these microbes directly into the mouth and stomach can increase the risk of localized infections in the oral cavity or the transfer of pathogenic bacteria to the gut.
The act of biting or picking the skin itself often creates small, open wounds that are prone to infection. Repeatedly chewing on these damaged areas exposes the wound to oral bacteria, increasing the likelihood of localized skin infections. Beyond infection, the repeated mechanical action of biting can cause damage to the teeth and gums over time, potentially leading to excessive wear on the tooth enamel or gum recession.
Gastrointestinal discomfort can also occur from the chronic ingestion of indigestible foreign matter. While extremely rare, excessive consumption of indigestible material carries the potential for a serious complication known as a bezoar. A bezoar is a tightly packed mass of foreign material that accumulates and fails to pass through the stomach or intestines, potentially requiring medical or surgical intervention.
Understanding Compulsive Skin Eating
When the behavior moves beyond an occasional nervous habit and becomes compulsive, it is often classified as a Body-Focused Repetitive Behavior (BFRB). The specific compulsion of biting and eating one’s skin is clinically referred to as dermatophagia. This disorder is recognized as being related to Obsessive-Compulsive and Related Disorders.
Dermatophagia is frequently triggered by emotional states such as stress, anxiety, or boredom, acting as a self-soothing or tension-relieving mechanism. The cycle often begins with the person seeking to smooth a perceived imperfection, which then leads to the repetitive picking and chewing.
The temporary relief or sensation experienced during the act reinforces the behavior, making it difficult to stop. The compulsion is not driven by hunger but by a psychological urge, and the behavior can become ritualistic, providing a brief sense of control or satisfaction.
Individuals who engage in this may experience feelings of shame or embarrassment due to the visible damage the habit causes to their skin. The severity of the behavior is determined by the extent of the damage and the degree to which it interferes with a person’s daily functioning and quality of life. Recognizing the psychological drivers behind the compulsion is an important step toward managing the behavior effectively.
Strategies for Managing the Behavior
A highly effective approach for managing dermatophagia is Habit Reversal Training (HRT), which involves increasing awareness of the behavior and replacing the compulsive action with a competing response. This training teaches individuals to identify the specific triggers and situations that precede the skin biting. Once the urge is recognized, the person learns to substitute the action with a harmless alternative.
Implementing stimulus control strategies can also help by creating physical barriers to the behavior. Simple measures like wearing gloves or keeping the affected skin covered with bandages can interrupt the automatic nature of the habit. These physical interruptions prompt conscious awareness, allowing the person to redirect the impulse.
For those whose behavior is severe or persistent, seeking professional help is recommended to address the underlying psychological factors. Cognitive Behavioral Therapy (CBT) can be beneficial in helping individuals manage the anxiety and stress that often fuel the compulsion. Mental health specialists can also recommend stress reduction techniques and explore other therapeutic approaches to develop healthier coping mechanisms.