Complex Regional Pain Syndrome
(CRPS; Reflex Sympathetic Dystrophy [RSD]; Causalgia; Sympathetically Maintained Pain)
Copyright © Nucleus Medical Media, Inc.
Definition
Complex regional pain syndrome (CRPS) refers to a chronic condition that affects the nerves and blood vessels of one or more limbs. Its features include unpleasant burning sensations, swelling, sweating, color changes, and other symptoms.
There are two types of CRPS:
- CRPS 1 (also called reflex sympathetic dystrophy or RSD)— No nerve damage is observable with this type.
- CRPS 2 (also called causalgia)—This produces similar symptoms after a verified nerve injury has occurred.
Causes
The cause of CRPS is not known. The condition likely results from several factors. It may involve overactivity of the sympathetic nervous system. This directs automatic body functions that a person cannot control. Inflammation may also play a role in the disorder.
Risk Factors
Factors that may increase your risk of CRPS include:
- Trauma
- Fractures
- Cuts
- Burns
- Frostbite
- Surgery
- Penetrating injury
- Crush injury
- An injection into the muscle
- Blood draws
- Diabetic neuropathy
- Multiple sclerosis
- Stroke
- Carpal tunnel syndrome
Symptoms
If you have any of these symptoms do not assume it is due to CRPS. These symptoms may be caused by other conditions.
The upper limbs, particularly the hands, are most commonly affected. Symptoms progress and may vary during the course of the condition. Pain may spread from one side of the body to another. Many doctors describe symptoms in terms of stages.
Within Hours or Days After Injury
Symptoms may include:
- Deep aching or burning pain, typically more severe than expected from the injury
- Sensitivity to touch or even a light breeze
- Swelling in the arm or leg
- Unusual sweating
- Excessively warm or cool skin
- Hair and nails changes
Symptoms may increase with stress and worsen over time.
3-6 Months After Injury
Symptoms may include :
- Burning pain above and below the initial injury
- Swelling in the arm or leg that hardens
- Muscle spasms or weakness
- Extremity that become cold
- Hair growth that is slow
- Nails that become brittle or crack
Six Months or Later After Injury
Symptoms may include :
- A pale, blue, and/or shiny look to the skin
- Limited joint movement
- Muscle loss
Diagnosis
Your doctor will ask about your symptoms and medical history. A physical exam will be done. To diagnose CRPS, the doctor uses four criteria:
- An initial traumatic or painful event to a limb, or keeping the limb still for a period of time
- Continuing pain in the limb that is out of proportion to any stimulus, such as pain with even light touch
- History of swelling, changes in skin blood flow, or temperature only in the affected limb
- No other cause for the symptoms
Tests may be ordered to rule out other conditions. Your doctor may refer you to a pain specialist for further evaluation and management. Tests may include the following:
- Pictures may need to be taken of your bodily structures. This can be done with:
- The electrical activity in your nerves and muscles may need to be tested. This can be done with:
- 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).
Treatment
Treatment aims to relieve pain and improve function. Visit the doctor as soon as possible. Early therapy may lead to better outcomes. In some cases, the condition goes away on its own; this is more common in children.
Treatment options include:
- Biofeedback
- Acupuncture
- Physical therapy—Active and passive exercises help maintain function. Exercising in a warm pool may feel better than exercising on land.
- Mirror bo