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Condition/Disorder Synonyms

  • Reflex sympathetic dystrophy (RSD)

  • Sudeck's atrophy

  • Reflex neurovascular dystrophy (RND)

  • Algoneurodystrophy

  • Causalgia

ICD-9-CM Codes

  • 337.21 Reflex sympathetic dystrophy of the upper limb

  • 337.22 Reflex sympathetic dystrophy of the lower limb

ICD-10-CM Codes

  • G90.519 Complex regional pain syndrome I of unspecified upper limb

  • G90.529 Complex regional pain syndrome I of unspecified lower limb

Preferred Practice Pattern1

Key Features


  • Autonomic changes

  • Severe pain, swelling, skin changes, inability to tolerate light touch

  • International Association for the Study of Pain (IASP) classification2

    • Type I: no nerve damage

    • Type II: nerve damage

Essentials of Diagnosis

  • Unknown cause

  • Electromyography (EMG)

  • Usually occurs near the site of injury

  • Three stages3

    • Stage 1 (inflammatory phase): severe burning, spasm, stiffness, skin changes, non-focal pain, decreased ROM

    • Stage 2 (vasomotor phase): symptoms of stage 1, plus muscle atrophy, osteoporosis, thickening of the dermis, cool skin temperature

    • Stage 3 (end stage): symptoms of stages 1 and 2, plus irreversible changes in skin and bones, flexor tendon contracture, atrophic stage

General Considerations

  • Fatigue, swelling, pain, sensory changes can cause disability

  • Deregulation of the autonomic system


  • Usually following injury or surgery

  • Three times more likely in females than males4

Clinical Findings

Signs and Symptoms

  • Pain

  • Sweating in the area

  • Inability to tolerate light touch

  • Deregulation of the autonomic system

  • Skin-color changes

  • Swelling

  • Nerve pain

  • Cracked nails

  • Osteoporosis

  • Muscle atrophy

  • Flexor tendon contracture

  • Skin-temperature change

  • Sympathetic hyperactivity

  • Associated symptoms may include paresthesias, burning, tingling

Functional Implications

  • Pain and stiffness can limit ALDs

  • Unable to use the extremity

  • Unable to wear socks

  • Unable to sleep due to pain from touching the sheets

Possible Contributing Causes

  • Unknown etiology

  • Surgery

  • Injury

  • Vascular disease

  • Spinal cord injury

  • Fracture

  • Frostbite

  • Amputation

  • Psychological components

  • Stress

  • Anxiety

Differential Diagnosis

  • Erythromelalgia

  • Myasthenia gravis

  • Chronic fatigue syndrome

  • Hypothyroidism

  • Lyme disease

  • Fibromyalgia

  • Peripheral nerve injury

  • Systemic lupus erythematosus

  • Rheumatoid arthritis

  • Polymyalgia rheumatica

  • Depression

  • Chronic neck and back pain

Means of Confirmation or Diagnosis


  • X-ray

  • Thermography

  • MRI

Diagnostic Procedures

  • Electromyography (EMG)

  • Widespread Pain Index (WPI)

  • Symptom severity score

  • Sympathetic block

  • Skin blood-flow test

Findings and Interpretation

  • X-ray and MRI negative

  • Laboratory tests negative



  • Sympathetic block

  • Cortisone



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