“tactile defensiveness: Being overly sensitive to touch; withdrawing, crying, yelling, or strking out when touched.
Some experts believe that that tactile defensiveness is related to disorganization in the midbrain, which is responsible for filtering incoming stimuli and—when abnormal—may not screen out all excessive tactile stimulation. As a result, a person would register even the most subtle sensations as irritating or painful, so that the person may respond to touch by grimacing or pulling away.
The central nervous system relies on different sensory nerve receptors in the skin to monitor the environment: light touch (surface), pressure (deep), temperature (hot and cold), and pain. It is quite possible for a person with tactile defensiveness to have one type of receptor that is oversensitive and the rest be normal. This explains why a person could tolerate light touch but pull away from a firm hug or prefer to run outside with a coat but be content with haircuts.
The tactile defensive individual can experience great distress in the course of daily life, constantly being bombarded with raw sensations. A person might insist on wearing only very soft clothes with large head openings or refuse to wear jewelry (especially around the neck). The slightest bump from another person may feel like a threat, and his or her defensive response may appear to be impulsive or aggressive. People with this condition may dislike group games such as tag or dodgeball, and holding hands with a partner can be physically agonizing. A person with this condition may shrink from being touched, which prevents him or her from being able to interact with friends in a normal way. Daily personal grooming, including bathing, washing hair, trimming nails, or brushing teeth can also be interpreted as uncomfortable.”
Excerpted from: Turkington, Carol, and Joseph R. Harris, PhD. The Encyclopedia of Learning Disabilities. New York: Facts on File, 2006.