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Complex Regional Pain Syndrome

What is complex regional pain syndrome?

Complex regional pain syndrome is a chronic condition that causes long-lasting pain. Normally, pain is temporary and resolves as the body heals. But with this condition, pain doesn't fade with time. Instead, it causes continuous pain that might get worse instead of better as days and weeks pass.

In the past, complex regional pain syndrome was called causalgia. Causalgia was first used to describe the symptoms of injured soldiers during the Civil War.

What causes complex regional pain syndrome?

Ex[erts aren't sure what causes complex regional pain syndrome, but they believe that nerve damage is involved. In most cases, the condition occurs after some type of injury to the affected area, although this is not always the case.

Doctor’s view this disease as an abnormal response by the body that magnifies the effects of the injury. The nerve endings that control pain in an area that has been injured may become overly sensitive to the chemical messengers carried by the sympathetic nervous system. These chemical messengers, called catecholamines, may stimulate the pain and other symptoms.

What are the symptoms of complex regional pain syndrome?

If you have complex regional pain syndrome, you may have the following symptoms:  

  • Persistent, burning pain in an arm, leg, hand, foot, or another part of your body
  • Pain can be mild or excruciating
  • Swelling
  • Sweating
  • Dramatic changes in skin color and skin temperature

How is complex regional pain syndrome diagnosed?

There are no tests that can diagnose complex regional pain syndrome with certainty. Doctors diagnose it mainly based on your medical history (such as having an injury) and the signs and symptoms you are having. But because several other conditions can cause similar symptoms, a careful physical exam is important. Sometimes tests are done to rule out some of these other conditions.

Your doctor may suggest a sympathetic nerve block (injection of an anesthetic into the nerves near the spine) to find out if your sympathetic nervous system is causing your pain. If the nerve block helps with your pain, your doctor may give you a series of nerve blocks for ongoing relief.

How is complex regional pain syndrome treated?

There is no cure for complex regional pain syndrome, but sometimes the symptoms get better or stop on their own. Some evidence suggests early treatment, particularly with physical therapy, can help limit the disorder, but this has not yet been proven in clinical studies.

Treatment focuses on relieving the pain, typically with one or more pain medications, antidepressants, antiseizure medicines, or oral steroid drugs. Other options include sympathetic nerve blocks, physical therapy, or electrical stimulation of the spinal cord or certain nerves. In severe cases, your doctor may inject medicines directly into the fluid around the spinal cord via a drug pump or surgically But it is not clear how effective these treatments are.

Living with complex regional pain syndrome

The outcome in complex regional pain syndrome can vary widely, so it is important that the condition is diagnosed and treated as soon as possible to give you the best chance for a full recovery. Be sure to follow your doctor's instructions for taking pain medicines and attending physical therapy or exercising if this is part of your treatment plan.

Physical therapy and exercise that keeps the painful limb or body part moving can often improve blood flow and lessen symptoms. It can also help improve the affected limb’s flexibility, strength, and function. If needed, occupational therapy can help you learn new ways to work and perform daily tasks.

Complex regional pain syndrome is a painful condition that can bring on emotional or psychological issues for those affected and their families. People with this condition might develop depression, anxiety, or post-traumatic stress disorder, all of which can make the pain seem worse and make rehabilitation efforts harder. Be sure to let your health care provider know how you are feeling, as there are often ways to help.

Some other types of therapies have been used to treat other painful conditions, such as behavior modification, acupuncture, relaxation techniques (biofeedback, progressive muscle relaxation, and guided motion therapy), and chiropractic treatment, but it is not clear if they are helpful for this condition. Be sure to talk with your health care provider before starting any new type of treatment.

When should I call my health care provider?

If you have been diagnosed with complex regional pain syndrome and are being treated, be sure to talk with your doctor or nurse about when you would need to call them.

Your doctor or nurse will likely advise you to call them if any of your symptoms get worse or if you develop any new symptoms.

Some people with this condition might need strong pain medicines, which can have their own side effects such as drowsiness, confusion, or changes in consciousness. Be sure to let your health care provider know if you have these or any other symptoms while taking pain medicines, as your doses might need to be adjusted.

Key points

  • Complex regional pain syndrome is a chronic condition that causes long-lasting pain. It is often caused by an overreaction in the body to a physical injury.
  • Symptoms include constant pain (ranging from mild to severe), sometimes along with swelling, sweating, and changes in skin color and temperature in the affected area.
  • Complex regional pain syndrome might resolve on its own over time, but in some people the symptoms can persist or even get worse. Common treatments include pain medicines, physical therapy, electrical nerve stimulation, and injecting an anesthetic into the nerves.

Next steps

Tips to help you get the most from a visit to your health care provider:

  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.
Online Medical Reviewer: Godsey, Cynthia, MSN, APRN, MSHE, FNP-BC
Online Medical Reviewer: Sohrabi, Farrokh, MD
Date Last Reviewed: 11/19/2013
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