Complex regional pain syndrome (CRPS) is a chronic neuro-inflammatory disorder with a probable autoimmune component in many individuals. It is a chronic pain syndrome most often characterized as constant, and extremely intense, regional pain usually following an injury to the region. As they respond to tissue damage from the injury or trauma, the nervous system and immune system malfunction . CRPS is thought to be caused by malfunction of or damage to either the peripheral or central nervous systems. Nerves misfire, sending constant pain signals to the brain. CRPS is subdivided into two types:

  • CRPS-I (formerly known as reflex sympathetic dystrophy): occurs in individuals without a direct injury to the nerves of the affected region
  • CRPS-II (formerly known as causalgia): occurs when there is an associated, confirmed nerve injury

CRPS is ranked on the McGill Pain Index as one of the most extreme manifestations of pain. According to the National Institutes of Health, patients with CRPS are usually found to have peripheral nerve abnormalities involving demyelination or thinly myelinated sensory nerve fibers. These nerve fibers carry pain messages and signals to blood vessels. Injury or damage to such fibers may lead to CRPS, as well as trigger damage in the spinal cord and brain.

Injury may also lead to the dilation of blood vessels or leakage of fluid into the surrounding tissue, causing the symptoms seen in CRPS patients. There is also an immune system component to CRPS. The tissue of individuals with CRPS often has high levels of cytokines (inflammatory chemicals) in their tissue, which further contribute to the symptoms associated with CRPS.


Connect with fellow pain warrior, Michelle Rice

The key symptom of CRPS is continuous, intense pain out of proportion to the severity of the injury, which gets worse rather than better over time. The condition most often affects one of the arms, legs, hands, or feet but, in rare cases, can travel to the opposite extremity and to other parts of the body.

Common features include:

  • Severe pain not associated to the initial trauma or injury, that does not cease or ease with healing of the trauma/injury
  • Dramatic changes in the color and temperature of the affected extremity or extremities, due to abnormal microcirculation caused by damage to the nerves controlling blood flow and temperature
  • Pain described as burning or pins and needles, and an increase in temperature from one extremity to the other (i.e. the affected leg is warmer to the touch than the unaffected leg)
  • Abnormal swelling and excessive sweating in the affected area
  • Changes in the growth of hair and nails in the areas surrounding the affected extremity
  • Extreme sensitivity and pain from something that should not cause pain, such as wind or touch
  • Stiffness and difficulty with proper movement, including weakness, spasms, limited range of motion, and atrophy
  • Texture of the affected area may appear shiny and thin
  • Hyperalgesia (excessive sensitivity to pain)

There is no specific test that can confirm CRPS. The diagnosis is based on a patient’s medical history, a physical examination, and lab results. The lab results are used by clinicians to rule out other conditions. The diagnosis can be made once all other diagnoses have been ruled out that explain the signs and symptoms.  


CRPS is not fully understood, and it is not clear why certain children and adults develop the condition while others don’t; however, the most common cause is trauma or injury to a nerve or multiple nerves of the peripheral or central nervous system. This trauma can be the result of something as simple as a cut or a needle prick or as serious as surgery or a stroke. About 90 percent of cases can be traced back to an injury or trauma. Immobilization furthers the likelihood of developing CRPS, so casted bones or stroke victims are more likely to develop CRPS.  Women are also at greater risk of developing CRPS with a 3.5:1 ratio.


There are currently no FDA-approved medications specifically for CRPS, although there are several different treatment options available to treat the condition. Make sure to visit www.clinicaltrials.gov to determine whether there are any ongoing clinical trials in your area.

Treatment depends on the severity and extent of nervous system involvement of the CRPS. It is commonly believed that the sooner an individual is diagnosed, the more likely their condition will go into remission: however, that is not always the case.

A full-body approach to treating CRPS is often used, including medications, physical therapy, and psychotherapy. While not all medications or treatment therapies may work, the following is a list of the most common treatment options physicians currently use.


  • An initial two-week trial of corticosteroids is often used during the acute phase
  • Anticonvulsants have been effective in treating neuropathic pain, including gabapentin, pregabalin, amitriptyline, nortriptyline, and duloxetine
  • Non-steroidal anti-inflammatory drugs such as over-the-counter aspirin and ibuprofen
  • Corticosteroids are often used to reduce swelling in the affected area, most often used in an acute phase for a limited period of time
  • Bisophosphonates, or medications used to prevent bone-loss, are prescribed to prevent the deterioration and weakening of muscles and bones in patients unable to move the affected extremity
  • Although opioids are not a medication of first choice for neuropathic pain, over 50% of individuals with CRPS do utilize opiates such as oxycodone, morphine, methadone, and hydrocodone
  • Low-dose naltrexone (LDN) is a compounded glia modulator which has shown great promise in published case studies
  • N-methyl-D-aspartate (NMDA) receptor antagonists such as dextromethorphan, memantine, and ketamine to help deal with the excitotoxicity which is implied to be involved in some neurodegenerative disorders
  • Topical local anesthetic creams

Other interventions:

  • Sympathetic nerve blocks are used to block the activity of the sympathetic nervous system; this treatment generally provides temporary relief and is designed to facilitate functional restoration
  • Spinal cord stimulation and other neurostimulation surgically implanted along the spinal cord, peripheral nerves, on the motor cortex (membranes or the brain), and within parts of the brain that control pain to provide electrostimulation to the injured nerves or the nervous system as a whole
  • Intrathecal drug pumps provide pain-relieving medications directly to the spinal fluid that covers the spinal cord. These medications typically include opioids, muscle relaxants, local anesthetics, and hypertension medications
  • Intravenous immunoglobulin (IVIG) is a newer therapy that intravenously provides the patient with a mixture of antibodies, which are proteins the body uses to fight infections
  • Visit clinicaltrials.gov to determine if a CRPS clinical trial is being conducted in your area


  • Behavior modification through talk therapy: due to the severe pain and lifestyle changes experienced because of CRPS, patients usually experience some degree of depression or anxiety which may be helped through therapy
  • Biofeedback is used to help an individual learn to control their body’s functions, namely the mind-body connection
  • Graded motor imagery and mirror box therapy are used by creating an illusion to trick the brain into thinking that the affected limb is healed/moving without pain

There are various types of complementary therapies that are recommended, including:

  • Yoga
  • Tai chi
  • Qi gong
  • Acupuncture

Any diet used should offer well-balanced food choices that will provide proper nutrition for the patient as a whole. Although there is not specific diet that has been studied at length to prove effectiveness in helping treat CRPS, there is reason to believe that eating anti-inflammatory, clean foods may provide some relief. However, patients should speak with their physicians before beginning a diet to ensure it’s medically appropriate.


Learn a little more with CRPS expert, Jim Broatch.
Disclaimer: The educational information provided is not a substitute for medical advice.  Always consult your primary care physician for diagnosis, treatment, and individual guidelines.