Complex regional pain syndrome (CRPS, formerly called reflex sympathetic dystrophy, or RSD) is a condition of severe localized pain. It is a form of "primary chronic pain". This means the pain is the primary problem or disease and is not a symptom of something else.

A person with CRPS often experiences a major painful or stressful event that is very hard on the body. This could include a trauma, infection, sprain, emotional stress or surgery. The body's nervous system reacts by causing the body to keep sending pain signals to the brain. The brain interprets these signals as ongoing injury. This may happen even if the original injury is completely healed. Most people with CRPS have pain in their arms or legs. Rarely, other body parts can be affected.

Who can get Complex Regional Pain Syndrome?

CRPS can happen in people of all ages, races, ethnic groups and genders. The typical pediatric CRPS patient is a teenage white female who injures her foot or ankle when playing a sport or dancing. Patients are usually good students who have a lot of stress or pressure in their lives. The pain can start in the foot, but the whole leg can become involved. The area is often cool, red- or blue-colored (or mottled), sometimes swollen and becomes so painful that even touching it lightly can be painful.

How is CRPS diagnosed?

CRPS is diagnosed by history and physical exam by a doctor. The International Association for the Study of Pain (IASP), which helped develop the term complex regional pain syndrome, has developed criteria that doctors use to diagnose CRPS.

There is no blood test or study like an X-ray or MRI scan that can tell your doctor if you have CRPS. On X-rays, osteoporosis can be seen, and bone scans have findings that are often seen in CRPS. Neither X-rays nor bone scans are helpful in making the diagnosis of CRPS, though. Usually, those tests are used to make sure nothing else is going on that needs a different type of treatment.

CRPS is often misdiagnosed. CRPS is rare. It is not high on the list of things to think about when a foot or hand hurts after an injury. After a painful event (such as surgery or trauma) the progression from acute injury pain to CRPS is not always obvious. Treatment of CRPS involves moving the hurting part to regain its function. But after an injury or surgery, it may be necessary to immobilize the extremity. Sometimes CRPS will set in, but it cannot be assessed until the splint or cast comes off. Pain doctors and some orthopaedic surgeons, neurologists and rheumatologists have experience in making the diagnosis.

What are symptoms of CRPS?

CRPS causes a person to experience severe pain out of proportion to things like gentle or light touch. Severe pain can occur even without stimulation or touch. Some people may have changes in their skin such as a pale, blue, red or a shiny appearance. A person may also notice swelling or stiffness in the area that is in pain. Some people feel a burning sensation, dryness or coolness of the body part involved. Sometimes hair and nails do not grow the same as on the other leg or arm. In CRPS, the nerves have changed in the way they work. They will continue to send signals to the brain that pain is happening, even when the original injury has healed. In fact, there are big changes that happen in the brain with CRPS. Those changes have been seen with advanced MRI imaging done in research programs.

The severe pain may cause a person to stop using their arm, leg or body part that is affected. If this lack of use (immobility) continues for a long time, the bones of that body part may lose calcium. On X-rays, osteoporosis may be seen. The muscles of that area also begin to atrophy (decrease in size) like someone who had their arm in a cast for several weeks.

How is CRPS Treated?

Treatment is focused on the different areas CRPS affects. Early diagnosis is important for preventing a prolonged course. The pain is coming from the affected body part and from changes that occur in the spinal cord and brain. Fortunately, there are treatments that successfully restore the person’s function and improve pain. Using an aggressive team approach, this treatment focuses on the different aspects of a person’s life that are affected by CRPS. A typical CRPS treatment team includes a physical or occupational therapist, a psychologist, a doctor, and a specialist nurse.

The aggressive treatment aims to break the cycle of pain by dealing with the different areas that CRPS can affect. A goal of treatment is to reprogram the nervous system to feel normal sensation and not just pain. Another goal is to regain strength and mobility of the affected body part. The different treatments for CRPS include:

• learning about the condition
• physical and occupational therapy to restore normal use of the affected body parts
• learning different coping and pain management skills like desensitization (exposing the painful body part to normal sensations to help teach the nerves the right thing to feel)
• medications

Regaining normal function is essential to recovery. Return to function almost always happens before the pain gets better. Unless there is a medical or surgical reason for the body part to be in a cast or splint, those devices should not be used. Preventing the body part from moving can make CRPS worse.

Can CRPS be Cured?

Yes. It is very hard work to get better from CRPS, but most kids and young adults will get better. Most of the time, the body can do normal activities before it begins to feel normal.