Nail biting
Nail biting, also known as onychophagy or onychophagia, is an oral compulsive habit. It is sometimes described as a parafunctional activity, the common use of the mouth for an activity other than speaking, eating, or drinking.
Classification
Nail biting is considered an impulse control disorder in the DSM-IV-R, and is classified under obsessive-compulsive and related disorders in the DSM-5. The ICD-10 classifies it as "other specified behavioral and emotional disorders with onset usually occurring in childhood and adolescence." Nevertheless, the frontier pathological nail biting is not clear.
Signs and symptoms
Nail biting usually leads to deleterious effects in fingers, but also mouth and more generally the digestive system. These consequences are directly derived from the physical damage of biting or from the hands becoming an infection vector. Moreover, it can also have a social impact.
The ten fingernails are usually equally bitten to approximately the same degree. Biting nails can lead to broken skin on the cuticle. When cuticles are improperly removed, they are susceptible to microbial and viral infections such as paronychia. Saliva may then redden and infect the skin. In rare cases, fingernails may become severely deformed after years of nail biting due to the destruction of the nail bed.