Complex regional pain syndrome (CRPS) is a condition marked by severe, prolonged chronic pain (lasting more than six months) that may be constant. Symptoms vary in intensity and duration. Some people describe it as a burning sensation, a "pins and needles" sensation, or as if an arm or leg is being squeezed. The pain may spread to the entire arm or leg, even though the injury may have been only to a finger or toe. Common symptoms include dramatic changes in the color and temperature of the skin over the affected limb or body part, accompanied by intense burning pain, increased sensitivity in the affected area, skin sensitivity, abnormal sweating, and abnormal movement in the affected limb. In most instances the condition is triggered by a clear history of trauma or injury. CRPS also affects the immune system -- the disorder is more common in individuals with other inflammatory and autoimmune conditions such as asthma. Limited data also suggests that CRPS may also be influenced by genetics.
There is no cure for CRPS and no drug has been approved specifically for the disorder. Treatments are aimed at relieving painful symptoms. Doctors may prescribe topical analgesics, antidepressants, corticosteroids, and opioids to relieve pain, but no single drug or combination of drugs has produced consistent long-lasting improvement in symptoms. Other treatments may include physical therapy, nerve blocks, spinal cord stimulation and other types of neurostimulation, and surgery.
The prognosis for CRPS varies highly from person to person. Early treatment, particularly rehabilitation, may help with limiting the disorder. Younger people, children, and teenagers tend to have better outcomes. Some older adults have good outcomes while others continue to experience severe pain despite treatment.
NINDS-supported scientists are studying new approaches to treat CRPS and intervene more aggressively to limit the symptoms and disability associated with the syndrome. For example, researchers hope to better understand how CRPS develops by studying immune system activation and peripheral nerve injury. Researchers also hope to identify specific cellular and molecular changes in sensory nerve cells following peripheral nerve injury. Identifying these mechanisms could provide targets for new drug therapies that could improve recovery following peripheral nerve injury and nerve cell regeneration. Information from the National Library of Medicine’s MedlinePlus Complex Regional Pain