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Harvard Medical School

Reflex Sympathetic Dystrophy Syndrome (RSDS)

What Is It?

Reflex sympathetic dystrophy syndrome (RSDS) is a severe, painful and long-lasting condition that usually involves one arm or leg. This condition has been called many other names, including algodystrophy, causalgia, shoulder-hand syndrome, Sudeck's atrophy and transient osteoporosis. In 1995, the name was changed officially to complex regional pain syndrome, or CRPS, although this name change has not been accepted universally.

The problem in RSDS is severe, constant, burning pain in the affected arm or leg.

The condition can be triggered by damage to nerve fibers in tissue that was injured in some way, but the cause of this syndrome remains unknown. Experts believe that in RSDS, nerves become overly sensitive. Painful signals become more painful, and common stimuli such as light touch and temperature changes also are experienced as pain.

This condition usually starts after an injury or other event, such as trauma, a fracture, an infection, surgery, a stroke or wearing a plaster cast. Often, the injury that triggers reflex sympathetic dystrophy syndrome is very mild compared with the pain that follows it. However, the condition also can follow more severe injury or paralysis. The pain often is not limited to the area that was injured. The earliest described cases were among Civil War soldiers in whom gunshot wounds that healed were followed over days to weeks by severe pain in arms or legs.

This condition can occur at any age and is relatively rare. It is most common in people between the ages of 40 and 60, but it is being diagnosed more frequently in children and adolescents. Researchers estimate that 12% to 21% of adults with paralysis on one side of the body and about 5% of adults with nerve injuries will develop RSDS.

In children with RSDS, girls are affected about two to four times more often than boys are affected.