Definition: Conditions characterized by pain involving an extremity or other body region, HYPERESTHESIA, and localized autonomic dysfunction following injury to soft tissue or nerve. The pain is usually associated with ERYTHEMA; SKIN TEMPERATURE changes, abnormal sudomotor activity (i.e., changes in sweating due to altered sympathetic innervation) or edema. The degree of pain and other manifestations is out of proportion to that expected from the inciting event. Two subtypes of this condition have been described: type I; (REFLEX SYMPATHETIC DYSTROPHY) and type II; (CAUSALGIA). (From Pain 1995 Oct;63(1):127-33)
