Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) refers to a chronic condition that affects the nerves and blood vessels of one or more limbs. There are two types of CRPS:

  • Causes

    The cause of CRPS is not known. The condition likely results from several factors. It may involve overactivity of the sympathetic nervous system. Inflammation may also play a role in the disorder.

  • Definition

    Complex regional pain syndrome (CRPS) refers to a chronic condition that affects the nerves and blood vessels of one or more limbs.

    There are two types of CRPS:

    • CRPS 1, previously called reflex sympathetic dystrophy or RSD, has no observable nerve damage.
    • CRPS 2, previously called causalgia, produces similar symptoms after a verified nerve injury has occurred.
    Complex Regional Pain Syndrome
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  • Diagnosis

    You will be asked about your symptoms and medical history. A physical exam will be done.

    The common characteristics of CRPS include:

    • An initial traumatic or painful event
    • Pain in the upper or lower extremities
    • A recent heart attack or stroke
    • Continuing pain in the limb that is out of proportion to any stimulus, such as pain with even light touch
    • Swelling, changes in skin blood flow,
      movement problems, or temperature

      changes
      only in the affected limb
    • No other cause for the symptoms

    Tests may be ordered to rule out other conditions. You may be referred to a pain specialist.

    Images may be taken of your bodily structures. This can be done with:

    • X-ray
    • CT scan
    • MRI scan
    • Bone scan


    The electrical activity in your nerves and muscles may need to be tested. This can be done with:

    • Nerve conduction studies
    • Electromyography

    You may need to have your body's heat measured. This can be done with a thermogram.

    You may need to have your autonomic nervous system evaluated. This can be done with quantitative sudomotor axon reflex test (QSART), resting sweat output (RSO), or the resting skin temperature (RST).

  • Prevention

    There are no known ways to prevent CRPS.

  • Risk Factors

    Factors that may increase your risk of CRPS include:

    • Trauma
    • Fractures
    • Limb immobilization
    • Longer than normal healing time
    • The use of certain medications such as ACE inhibitors

  • Symptoms

    Symptoms usually appear after an injury. The most important symptom of CPRS is prolonged pain that may be constant or severe. Pain is typically described as burning, throbbing, aching, squeezing, or shooting.

    Symptoms of CRPS change over time and may include:

    • Sensitivity to touch or even a light breeze
    • Swelling in the arm or leg
    • Unusual sweating patterns
    • Excessively warm or cool
      skin
    • Hair and nails that become brittle and crack
    • Abnormal movement in the arm or leg, such as a tremor, jerking, or spasms
    • A pale, blue, and/or shiny look to the skin
    • Limited joint movement

  • Treatment

    Treatment aims to relieve pain and improve function. Early therapy may lead to better outcomes. In some cases, the condition goes away on its own; this is more common in children. Talk with your doctor about the best treatment plan for you. Options include: