Dermatophagia (sufferers can be called wolf-biters) is a type of Impulse Control Disorder and Obsessive Compulsive Disorder wherein a sufferer compulsively bites their own skin. Sufferers typically bite the skin around the nails, leading to bleeding and discoloration over time. Some may consume the flesh during an episode.
The behavior associated with skin-biting is not exclusively the compulsory response to anxious/obsessive cognition; it is impulsive, and while the skin-biting may present with anxiety/obsessive thoughts, the presence of anxiety/obsessions is not diagnostically required to precede the behavior (while such anxiety/obsessions are diagnostically required with OCD).
However, contemporary research suggests a link between impulse control disorders and Obsessive Compulsive Disorders, and this is rumored to be addressed in the DSM 5, due for publication in May 2013. Further information on differentiation between OCD, other anxiety disorders, and Dermatophagia and other impulse-control disorders can be found in the DSM-IV TR.