Complex Regional Pain Syndrome (CRPS) / Reflex Sympathetic Dystrophy (RSD)
Complex regional pain syndrome (CRPS), previously referred to as reflex sympathetic dystrophy (RSD), is a condition resulting in burning pain, stiffness, swelling, and discoloration of the hand. CRPS includes other medical diagnoses, including causalgia, Sudeck's atrophy, and shoulder-hand syndrome. CRPS occurs as result of abnormally overactive sympathetic nervous system that controls the blood flow and sweat glands in an extremity. A burning pain, swelling, and warmth are felt in the affected extremity. If not treated, CRPS can cause stiffness and a loss of use of the affected extremity. In the worse cases, the results can be permanent
The cause of CRPS is frequently unknown. CRPS is felt to occur as the result of stimulation of sensory nerve fibers. Those regions of the body rich in nerve endings such as the fingers, hands, wrist, and ankles are most commonly affected. Often, an injury can cause CRPS, especially when placing pressure on the nerves such as in a crush injury. CRPS commonly occurs after an injury as minor as having blood drawn, or a sprained ankle. Other times, it may be the result of a more significant injury such as surgery, a fracture, immobilization with casting or splinting, or the result of a stroke. Other causes include infection, cancer, neck or low back disorders, stroke, or heart attack. These conditions can cause pain, which sets off the sympathetic reflex, causing symptoms of CRPS. Nerve injuries may change the way the nerve impulses are sent, causing a "short circuit." Risk factors for developing CRPS include immobilization of the affected limb; smoking; genetics; and psychological factors.