Complex Regional Pain Syndrome.

Complex regional pain syndrome (CRPS) has been described as pain a patient feels that is disproportionate to the inciting event. CRPS is also associated with autonomic dysfunction, swelling, dystrophic skin changes, stiffness, functional impairment, and eventual atrophy. This hyperalgesic disease affects musculoskeletal, neural, and vascular structures more commonly in the upper extremity than the lower extremity. Although the etiology behind the pathophysiology of CRPS is unknown, the pain pathway extending from peripheral nociception to central nervous system modulation of stimuli is highly sensitized and overactive, disrupting the surrounding autonomic response. The diagnosis and treatment of CRPS are reviewed.