Reflex Sympathetic Dystrophy Syndrome (RSDS)—also known as Complex Regional Pain Syndrome (CRPS)—is a chronic pain condition that can affect any area of the body, but often affects an arm or a leg.

RSDS has two forms:

• Type 1 is a chronic nerve disorder that occurs most often in the arms or legs after a minor injury or infection.
• Type 2 is caused by an injury to a nerve.

RSDS is thought to result from damage to the nervous system, including the nerves that control the blood vessels and sweat glands. The damaged nerves are no longer able to properly control blood flow, feeling (sensation), and temperature to the affected area. Rarely, sudden illnesses such as a heart attack or stroke can cause RSDS. The condition can sometimes appear without obvious injury to the affected limb.

This leads to medical problems in the blood vessels, bones, muscles, nerves, or skin.

The condition is more common in people 40–60 years of age, but it has been seen in younger people.

Symptoms

The main symptom is continuous, intense pain out of proportion to the severity of the injury, and which gets worse rather than better over time. The pain usually begins at the point of injury, but often spreads to the whole limb, or to the arm or leg on the opposite side of the body.

In most cases, RSDS has three stages. However, RSDS does not always follow this pattern. Some people develop severe symptoms almost right away. Others stay in the first stage.

Stage 1 (lasts 1 – 3 months) involves changes in skin temperature, switching between warm or cold, faster growth of nails and hair, muscle spasms and joint pain, severe burning, aching pain that worsens with the slightest touch or breeze – and skin that slowly becomes blotchy, purple, pale or red, swollen, and more sweaty.

Stage 2 (lasts 3 – 6 months) involves continued changes in the skin, nails that are cracked and break more easily, pain that is becoming worse, slower hair growth, and stiff joints and weak muscles.

Stage 3 involves limited movement in limb because of tightened muscles and tendons (contracture), muscle wasting, and pain in the entire limb. Irreversible changes can be seen.

If pain and other symptoms are severe or long-lasting, many people may experience depression or anxiety.

Signs and Tests

Diagnosing RSDS can be difficult, but early diagnosis is very important.

The doctor will take a medical history and do a physical examination. Other tests may include a test to show temperature changes and lack of blood supply in the affected limb (thermography), bone scans, nerve conduction studies, and X rays.

Treatment

There is no cure for RSDS, but the disease can be slowed. The primary focus is on relieving the symptoms and helping people with this syndrome live as normal a life as possible.

Physical and occupational therapy should be started as early as possible. Starting an exercise program and learning to keep joints and muscles moving may prevent the disease from getting worse and help the patient perform everyday activities.

Medications may be used, including pain medicines, steroids, certain blood pressure medicines, bone loss medications, and antidepressants.

Some type of talk therapy, such as cognitive behavioral therapy or psychotherapy, can help teach the skills needed to live with chronic pain.

Some surgical or invasive techniques have been used:

• Injected medicine that numbs the affected nerves or pain fibers around the spinal column (nerve block);
• Internal pain pump that directly delivers medications to the spinal cord (intrathecal drug pump);
• Spinal cord stimulator, which involves placing electrodes (electrical leads) next to the spinal cord. A low-level electrical current is used to create a pleasant or tingling sensation in the painful area, which may help distract from the pain;
• Surgery that cuts the nerves to destroy the pain (surgical sympathectomy), although it is unclear how many patients this helps. It may also make some patients' symptoms worse.

Expectations

The outlook is better with an early diagnosis. If the doctor diagnoses the condition within the first stage, sometimes signs of the disease may disappear and normal movement may be possible.

In some people, symptoms go away on their own. In other people, even with treatment the pain continues and the condition causes crippling, irreversible changes.

Complications may include loss of muscle size or strength in the affected limb, spread of the disease to another part of the body, or worsening of the affected limb. Complications also can occur with some of the nerve and surgical treatments.

Contact your health care provider if you develop constant, burning pain in an arm, leg, hand, or foot.

Prevention

There is no known prevention at this time. Early treatment is the key to slowing the progression of the disease.

Information in this article was adapted from an RSDS fact sheet from the National Institute of Neurological Disorders and Stroke, National Institutes of Health.

Links

• Reflex Sympathetic Dystrophy Syndrome Association (RSDSA)
• National Institutes of Health, Institute of Neurological Disorders and Stroke — RSDS Page