Onychophagia (also onychophagy) or nail biting, is an oral compulsive habit (sometimes described as a parafunctional activity; the common use of the mouth for an activity other than speaking, eating or drinking.)
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 between normal and a 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.
Nail biting is also related to oral problems, such as gingival injury, and mal occlusion of the anterior teeth. It can also transfer pinworms or bacteria buried under the surface of the nail from the anus region to the mouth. When the bitten-off nails are swallowed, stomach problems can develop.
Nail-biting is also associated to guilt and shame feelings in the nail biter, a reduced quality of life, and increased stigmatization in the inner family circles or at a more societal level.
Stress, Anxiety and Depression are also main cause for Nail Biting which can be reduced through Yoga, Pranayama and meditative techniques. Diversion during the crises of stress helps in overcoming nail biting.