Injury to the affected limb results in misfiring in the sympathetic nervous system loop causing reflexive vasospasm in the limb leading to swelling, color change, and pain.
REFLEX SYMPATHETIC DYSTROPHY
An injury to a portion of the nervous system may occur from trivial trauma (cut, contusion) or from a major injury to the nerve that may crush or cut the nerve. Pain is usually out of proportion to what would normally be expected from the condition. Significant burning and pain is the earliest symptom. Swelling is the most constant physical finding, which if not treated early is often followed by rapid onset of stiffness. Other signs may be variable and may include movement disorders, skin discoloration or excessive sweating. Late changes may include smooth, shiny or dry skin with an abnormal color and a cool temperature, difficulty moving the entire extremity. Weight-bearing may become very difficult, requiring long-term use of a brace. Whenever possible the underlying cause of this syndrome should be sought. Immediate physical therapy and oral medication are necessary. When severe, a pain management specialist may provide nerve blocks to attempt to eliminate the pain and burning. A multi-specialty approach is necessary for the treatment of this condition including a podiatrist, neurologist, physical therapist and pain management specialist. This may become a permanent condition if not treated early and effectively.