Introduction to Allodynia
Allodynia is a medical condition that causes an individual to experience pain from stimuli that do not typically cause pain. For example, a normal everyday touch, such as a sleeve brushing against the arm, a brush combing through the hair, or light pressure applied on the skin from a piece of clothing results in pain. The pain experienced is different for each individual with allodynia.
Allodynia is classified into three types: static or tactile, mechanical or dynamic, and thermal. Static or tactile allodynia is diagnosed when allodynia pain occurs as a result of pressure applied to the skin. Mechanical or dynamic allodynia is diagnosed when allodynia pain occurs as a result of movement over the skin. Thermal allodynia is diagnosed when allodynia pain occurs as a result of a change of temperature to the skin.
Allodynia can develop on its own or as the result of another condition. The exact reason why allodynia surfaces is not known, but it is thought to involve increased receptiveness or malfunction of nociceptors, a type of nerve.
Medical conditions that may have allodynia as a symptom include, but are not limited to, the following: