Dermatophagia

Background
Dermatophagia (sufferers can be called wolf-biters) is a form of neurodermatosis wherein a sufferer habitually bites their skin. It often takes the form of chewing on the fingers, and when left unchecked, can lead to discoloration and damage.

Behavior
Sufferers of dermatophagia often chew their skin out of habit or compulsion, and can do so on a variety of places on their body. Commonly, it seems to manifest in the fingers, where the skin around fingernails and surrounding joints get the brunt of the damage. If the behavior is left unchecked for an extended period, callouses may start to develop where most the biting is done.

Skin chewing can be bolstered by times of apprehension and other unpleasant events. Another disorder, known as dermatillomania, the act of peeling one's skin, can sometimes accompany dermatophagia.