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For further information, see CMDT Part 20-47: Complex Regional Pain Syndrome

Key Features

Essentials of Diagnosis

  • Rare disorder characterized by autonomic and vasomotor instability

  • Intense, burning pain; often greatly worsened by minimal stimuli, such as light touch

General Considerations

  • Formerly called reflex sympathetic dystrophy

  • Most cases are preceded by direct physical trauma, often of relatively minor nature, to the soft tissues, bone, or nerve

  • May occur after a knee injury or after arthroscopic knee surgery

  • Any extremity can be involved, but the hand is most commonly affected and is associated with ipsilateral restriction of shoulder motion (shoulder-hand syndrome)

  • The shoulder-hand variant sometimes complicates myocardial infarction or injuries to the neck or shoulder

  • The posttraumatic variant is known as Sudeck atrophy

Clinical Findings

Symptoms and Signs

  • No systemic symptoms

  • Localized pain

  • Swelling of involved extremity

  • Disturbances of color and temperature in affected limb

  • Dystrophic changes in overlying skin and nails

  • Limited range of motion

  • Findings are not limited to the distribution of a single peripheral nerve

Differential Diagnosis

  • Other cervicobrachial pain syndromes

  • Rheumatoid arthritis

  • Thoracic outlet obstruction

  • Systemic sclerosis (scleroderma)


Imaging Studies

  • Bone scans

    • Sensitive in the early phases

    • Show diffuse increased uptake in affected extremity

  • Radiographs eventually reveal severe generalized osteopenia



  • Nortriptyline

    • Initial dose: 10 mg orally at bedtime

    • Increase gradually to 40–75 mg at bedtime

  • Gabapentin, 300 mg three times daily orally

  • For mild cases, NSAIDs (eg, naproxen 250–500 mg twice daily orally) can be effective

  • For more severe cases associated with edema, prednisone, 30–60 mg/day orally for 2 weeks and then tapered over 2 weeks, can be effective

  • Bisphosphonates, calcitonin, regional nerve blocks, and dorsal-column stimulation have been reported to be helpful

Therapeutic Procedures

  • Patients with restricted shoulder motion may benefit from physical therapy for scapulohumeral periarthritis

  • Regional nerve blocks and dorsal-column stimulation



  • Good with early treatment


  • Early mobilization after injury, surgery, or myocardial infarction


Chang  C  et al. Complex regional pain syndrome—false hopes and miscommunications. Autoimmun Rev. 2019;18:270.
[PubMed: 30639650]  
Rand  SE  et al. Complex regional pain syndrome: current diagnostic and treatment considerations. Curr Sports Med Rep. 2019;18:325.
[PubMed: 31503044]  

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