Regional Pain Syndrome

1 What is Complex Regional Pain Syndrome?

Complex regional pain syndrome is a chronic neuro-inflammatory disorder characterized by intense, burning pain in your arm or leg.

The exact cause of complex regional pain syndrome has been fully explained.

Generally, complex regional pain syndrome is triggered by an injury, fracture, amputation, surgery, stroke or heart attack.

Early treatment is sought for complex regional pain syndrome as early intervention produces better outcomes.

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2 Symptoms

Signs and symptoms of complex regional pain syndrome include:

  • Continuous burning or throbbing pain, usually in your arm, leg, hand or foot
  • Hypersensitivity (to touch or cold)
  • Swelling of the affected area
  • Abnormal changes in skin temperature
  • Abnormal changes in skin color
  • Tender, thin or shiny skin
  • Abnormal changes in hair and nail growth
  • Joint stiffness, swelling and damage
  • Muscle weakness and loss (atrophy)
  • Limited range of motion

Symptoms may be patient specific and tend to change over time. Initially, typical symptoms like pain, swelling, redness, abnormal changes in temperature and hypersensitivity (particularly to cold and touch) are observed on the affected region.

The progression of the disorder is marked by color and temperature changes, muscle spasms, nail changes and tightening in the affected limb. From this stage, the disorder often becomes irreversible. The pain is spreading and may be worsened by emotional stress. In some people, the signs go away on their own while in some, it may persist for months to years.

When to see a doctor

Consult your doctor if you experience severe, persistent, burning pain especially if you think you are at a greater risk of the disease.

Early diagnosis followed by early treatment is shown to produce better therapeutic outcomes.

3 Causes

On the basis of the causative factor, Complex regional pain syndrome is divided into two types:

  • Type 1: Also called Reflex sympathetic dystrophy syndrome, it is the common type which accounts for 90 percent of complex regional pain syndrome cases. It is triggered by an apparent trivial injury, such as a fractured or sprained ankle.
  • Type 2: Once referred to as Causalgia, this type is triggered by more serious injury like broken bone, crush injury, fracture or amputation and certain surgery that cause a distinct nerve damage.

Why these injuries can trigger complex regional pain syndrome is still unclear however it is possibly due to an abnormal neuro-inflammatory response.

4 Making a Diagnosis

Diagnosis of complex regional pain syndrome is based on a physical exam and your medical history.

Prepare yourself for the appointment with these tips.

What you can do

Make a list of the symptoms. Mention the severity and location of your pain, stiffness or sensitivity.

Write down the questions to ask your doctor, like:

  • What could be the possible cause for my symptoms?
  • Is my condition temporary or chronic?
  • What are the tests for the condition?
  • What are the treatment options?
  • Where can I learn more about my condition?

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on.

For complex regional pain syndrome, your doctor may ask:

  • Have you had a recent accident, illness or injury, such as trauma to your limbs, a heart attack or an infection?
  • Have you had surgery recently?
  • When did you first begin experiencing pain or burning?
  • How long have you been experiencing your symptoms?
  • Is the pain occasional or continuous?
  • Does anything seem to improve or worsen your symptoms?
  • Have you experienced similar symptoms after past injuries?

There's no single test that can definitively diagnose complex regional pain syndrome, but the following procedures may provide important clues:

Bone scan

This procedure may help detect bone changes. A radioactive substance injected into one of your veins permits viewing of your bones with a special camera.

Sympathetic nervous system tests

These tests look for disturbances in your sympathetic nervous system. For example, thermography measures the skin temperature and blood flow of your affected and unaffected limbs.

Other tests can measure the amount of sweat on both limbs. Dissimilar results can indicate complex regional pain syndrome.


Loss of minerals from your bones may show up on an X-ray in later stages of the disease.

Magnetic resonance imaging (MRI)

Images captured by an MRI device may show a number of tissue changes.

5 Treatment

Early treatment for complex regional pain syndrome, within a few months of your first symptoms, yields better outcomes or even remission. Due to complexity of the pain and associated symptoms, your doctor may recommend a combination of therapies.

Treatment options include:


Over-the-counter (OTC) pain relievers such as aspirin, ibuprofen and naproxen can be prescribed to alleviate moderate pain and inflammation. Your doctor may prescribe opioid pain relievers if OTC pain relievers are ineffective.

  • Antidepressants and anticonvulsants: Pain arising due to nerve damage (neuropathic pain) may be treated by antidepressants, such as amitriptyline, and anticonvulsants, such as gabapentin.
  • Corticosteroids: Your doctor may prescribe steroids like prednisone to treat inflammation and swelling. These drugs are generally used in the early stages.
  • Bone-loss medications: To prevent or reduce bone loss, your doctor may prescribe drugs like alendronate and calcitonin.
  • Sympathetic nerve-blocking medication: It involves injecting an anesthetic next to the spine to directly block the activity of sympathetic nerves and improve blood flow.
  • Intravenous ketamine: According to some studies, low doses of intravenous ketamine, a strong anesthetic may significantly relieve the pain.


  • Applying heat and cold: Applying hot or cold on the affected region can provide warmth or reduce sweating, respectively.
  • Topical analgesics: Locally applied treatments, such as capsaicin cream or lidocaine patches may be used to reduce hypersensitivity.
  • Physical therapy: Simple, non-impact exercises under supervision may help decrease pain and improve range of motion and strength.
  • Transcutaneous electrical nerve stimulation (TENS): TENS is a form of electroanalgesia in which nerve endings are stimulated by low voltage electrical impulses. It may help be helpful in chronic pain management.
  • Spinal cord stimulation: Tiny stimulating electrodes placed near your spinal cord produce tingling sensations in the area of pain thus providing pain relief.

Recurrences of complex regional pain syndrome can sometimes occur due to a trigger such as exposure to cold or an intense emotions. In such case, low doses of antidepressants may provide relief.

6 Prevention

Your risk of complex regional pain syndrome may be prevented by:

  • Taking Vitamin C after a wrist fracture: Studies suggest taking 500mg vitamin C daily after a wrist fracture could lower risk of complex regional pain syndrome.
  • Early mobilization after a stroke: According to some research, early mobilization lowers the risk of complex regional pain syndrome.

7 Lifestyle and Coping

Lifestyle modifications are necessary in order to cope with complex regional pain syndrome.

Living with severe, chronic pain is a challenge and it takes loads of courage and substance to carry on.

Following suggestions could make your pain a little bearable:

  • Maintain your daily activities, as far as possible.
  • Stay close to friends and family.
  • Continue to pursue hobbies that you enjoy and you are capable of.
  • Keep in mind that your physical health and mental health are closely linked and disturbance to one can affect the other.
  • You may be feeling down due to denial, anger and frustration. Understand that these symptoms are common with every chronic illness. Talk to your therapist, behavioral psychologist or other professional. They can teach you coping skills such as relaxation or meditation techniques.
  • Join a support group: Sharing your pain and feelings with other similar people can make you satisfied and happy with the life.

8 Risks and Complications

If not treated at its earliest, complex regional pain syndrome can lead to various complications like:

  • Tissue wasting (atrophy): The pain and stiffness in the limbs might limit their use. If not used for a long time, your skin, bones and muscles may weaken and degenerate.
  • Muscle tightening (contracture): Limited movement can also result into tightening of your muscles.

9 Related Clinical Trials