Reflex sympathetic dystrophy of the lower extremity

Reflex sympathetic dystrophy (RSD) is a complex syndrome of pain, trophic changes, and vasomotor instability secondary to an abnormal hyperactive state of the sympathetic nervous system following injury to an extremity. Numerous theories have been proposed to explain the pathophysiology. None is universally accepted. The diagnosis of RSD is complicated because some patients improve without treatment, whereas others develop intractable symptoms even after the injury has healed. A delay in diagnosis and/or treatment for this syndrome can result in severe physical and psychological problems. Early recognition and prompt treatment, i.e., sympathetic blockade and physical therapy, provide the greatest opportunity for a successful outcome.