Reflex Sympathetic Dystrophy (RSD) is another, older name for Complex Regional Pain Syndrome (CRPS). CRPS is a chronic pain and sensory condition that mainly affects the arms and legs. Two types of CRPS exist: Type I is characterized by persistent pain and swelling caused by trauma to an area that produces vasomotor disorders and Type II is caused by a direct and specific injury to a nerve. Type I is much more common than Type II.
The two main symptoms of CRPS are allodynia and hyperalgesia. Allodynia is the name for the pain produced by a source that would not usually be painful – an example would be bed sheets touching your skin and causing pain. Hyperalgesia is defined as a disproportionate reaction to a mildly painful stimulus.
CRPS is most commonly seen after a traumatic leg or arm injury, and is believed to be a development of both the peripheral and central nervous systems. The doctor may perform a physical exam to find areas of tenderness and limitations in movement. Imaging may be ordered to confirm their suspicions.
The effectiveness of treating CRPS largely depends on how quickly the patient seeks treatment. One procedure available for CRPS is a sympathetic nerve block. Physical therapy, non-steroidal anti-inflammatory medications (NSAIDs) and cognitive behavioral therapy may also be considered to treat the symptoms and effects of chronic pain. For some patients, spinal cord stimulation or peripheral nerve stimulation may be the best treatment option.