Some simple actions like biting nails or pulling out a grey hair, might be viewed as normal but, in rare cases, this activity can be accompanied by auto-cannibalism, in which a person may eat that hair or nail.

Auto-cannibalism is a mental health disorder that’s primarily characterised by the ‘compulsion to eat oneself’, according to Healthline. In the article, ‘All about Auto-cannibalism’ published by the site, it should be noted that an edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) doesn’t recognise this disorder as a diagnosable mental health disorder.

Dr Janvier Yubahwe, a psychiatrist at Huye Isange Rehabilitation Center, says that auto-cannibalism, also known as self-cannibalism or auto-sarcophagy, is the practice of eating oneself. 

He says that it is a very rare condition, and is considered self-injuring behaviour that requires deep assessment to understand the underlying causes so as to determine appropriate management. 

"It has been reported among patients with underlying medical conditions such as sepsis (a condition resulting from the presence of harmful microorganism in the blood and other tissues and leading to multiple organ failure) and individuals with lack of exogenous nutritional support,” he says.

Health experts say that forms aren’t extreme as most people who practice auto-cannibalism don’t engage in extreme self-cannibalism. Instead, the more common forms include eating things like, scabs, nails, skin and hair, among others. 

Yubahwe notes that auto-cannibalism can also be found among patients with mental disorders like, schizophrenia, where the hallucinations tell the individual to eat him/herself.

"Also, mental retardation and malingering which is an intentional production or feigning of either physical or psychological symptoms motivated by external stresses or incentives,” he adds.  

Experts say that mental health conditions that can be classified as auto-cannibalism include: 

Allotriophagia, also known as pica, as this happens when a person eats items that have no nutritional value. These can include relatively harmless non-food items such as ice or more harmful items such as paint chips.

Another condition is onychophagia, which is characterised by an uncontrollable urge to eat the nails. Unlike the anxious habit of nail-biting, this condition causes considerable damage to the fingernails. 

The third one is dermatophagia; this is characterised by eating the skin on the fingers or hands. This condition is more serious than simply picking at a hangnail, and it often leads to skin that is damaged and bleeding. 

There is also trichophagia, also known as Rapunzel syndrome, this happens when a person feels compelled to eat their own hair. Since hair can’t be digested, this can lead to blockages or infections in the digestive tract.

Healthline states that signs of auto-cannibalism may differ depending on the type and severity of the disorder. These include damage to the body. All types of auto-cannibalism can cause damage to the body, such as, bruising, bleeding, scarring, discoloration, nerve damage and infection. Or gastrointestinal (GI) issues like nausea, pain, stomach ulcers, blood in the stool, blockages or damage to the GI tract.

If such conditions are left untreated, auto-cannibalism can lead to scarring, infections, and in some cases, severe complications that may cause death.

Yubahwe explains that the dangers of auto-cannibalism are many and range from lack of cosmetics to sepsis and its complications via infected wounds.  The treatment will always rely on the management of the underlying causes but also that of the self-inflicted injuries.