Complex regional pain syndrome I in the upper extremity.

Complex regional pain syndrome (CRPS) I, formerly known as reflex sympathetic dystrophy (RSD), is a painful neuropathic condition that most commonly affects a traumatized extremity. It is characterized by pain that is out of proportion to the original injury, has a distal predominance, and is not attributable to a specific peripheral nerve injury. The name RSD has been changed to CRPS I reflecting the fact that although sympathetic dysfunction can maintain the painful state, it is not the essential pathophysiologic lesion. Successful treatment hinges on early recognition of suspected cases, prompt referral to pain specialists, and ultimately pain control and return of limb function. Treatments range from noninvasive medications and therapies to sympathetic ganglion blockade and sympathectomy. The sports medicine physician is in an ideal position to recognize CRPS I in its earliest stages postinjury, and is advised to make prompt referral to a pain specialist when suspected.