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What Is Complex Regional Pain Syndrome?

  • Writer: Dr John Hong
    Dr John Hong
  • May 12
  • 3 min read

John K. Hong, M.D. | 5/12/2025





CRPS is a neuropathic pain condition characterized by prolonged or excessive pain and changes in skin color, temperature, or swelling in the affected area. It typically develops after a trauma, fracture, surgery, or even a minor injury and is most commonly seen in the arms, hands, legs, or feet.


CRPS is believed to result from dysfunction in the central or peripheral nervous system, leading to abnormal inflammation and nerve signaling.


Types of CRPS


There are two main types of CRPS:

  • CRPS Type I (Reflex Sympathetic Dystrophy)

    • Occurs without a confirmed nerve injury

    • Accounts for ~90% of CRPS cases

    • Often triggered by soft tissue injury, fracture, or surgery

  • CRPS Type II (Causalgia)

    • Occurs with a known nerve injury

    • Usually follows a direct trauma to a major nerve

    • Symptoms tend to be more focal and intense

Despite the classification, both types share similar symptoms and are treated using similar principles.


Clinical Presentation: Recognizing CRPS


CRPS symptoms typically develop within weeks of an injury and may progress through stages. Common features include:

  • Severe, burning, or stabbing pain disproportionate to the original injury

  • Allodynia: Pain from normally non-painful stimuli (e.g., light touch)

  • Hyperalgesia: Exaggerated pain response

  • Swelling and edema

  • Changes in skin color and temperature (red, blue, pale; hot or cold)

  • Abnormal sweating

  • Hair and nail growth changes

  • Motor symptoms: Tremors, weakness, dystonia, or reduced range of motion

  • Joint stiffness and muscle atrophy over time

CRPS often follows a non-dermatomal distribution, making it difficult to diagnose without clinical expertise.


Diagnosis of CRPS


There is no single test for CRPS. Diagnosis is clinical, based on:

  • History of trauma or surgery

  • Presence of pain and sensory, vasomotor, sudomotor, or motor/trophic symptoms

  • Use of the Budapest Criteria, the most accepted diagnostic guideline

Imaging studies such as bone scans or MRI may support the diagnosis but are not definitive.


Treatment Options for CRPS


Early, multidisciplinary treatment is essential. A combination of medical, physical, and interventional therapies offers the best chance of symptom control and functional recovery.


1. Medications

  • Neuropathic agents: Gabapentin, pregabalin, amitriptyline, duloxetine

  • NSAIDs or corticosteroids during acute inflammatory phases

  • Bisphosphonates: Sometimes used to reduce bone changes and pain

  • Low-dose naltrexone (LDN): Investigational but promising in some cases

2. Physical and Occupational Therapy

  • Central to CRPS treatment

  • Emphasis on graded motor imagery, desensitization, and maintaining mobility

  • Prevents muscle wasting and joint stiffness

3. Psychological Support

  • High rates of anxiety, depression, and PTSD in CRPS patients

  • Cognitive behavioral therapy (CBT) and pain coping strategies are beneficial

4. Interventional Pain Management

  • Sympathetic nerve blocks (e.g., stellate ganglion or lumbar sympathetic block)

  • Spinal cord stimulation (SCS): FDA-approved for CRPS; highly effective in refractory cases

  • Intrathecal therapy or peripheral nerve stimulation in select cases

5. Emerging and Adjunctive Therapies

  • Scrambler Therapy: Neuromodulation that re-trains the nervous system with “non-pain” signals

  • Ketamine infusions: NMDA receptor antagonist with promising results in severe cases

  • Mirror therapy and virtual reality rehab


Prognosis and Long-Term Outlook


  • Early treatment significantly improves the chance of recovery.

  • Mild to moderate CRPS often responds well to physical therapy and medications.

  • Severe or long-standing CRPS may require advanced neuromodulation or interventional techniques.

  • CRPS can remit, but it can also become chronic without proper management.


Conclusion


Complex Regional Pain Syndrome is a difficult but treatable condition. With early recognition and a comprehensive, multidisciplinary approach, many patients experience significant improvement and return to functional activities. Interventional pain physicians play a vital role in diagnosis, coordination of care, and delivery of advanced treatments like nerve blocks and spinal cord stimulation.


If you are experiencing chronic pain and would like more information or to schedule a consultation, contact our clinic today at (435) 714-7180. Parkview has offices in Park City and Salt Lake City to conveniently serve you!


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