Complex Regional Pain Syndrome (RSD)

Complex Regional Pain Syndromes are painful conditions that usually affect the distal part of an upper or lower extremity and are associated with characteristic clinical phenomena.

The term “Complex Regional Pain Syndrome” was introduced to replace the terms “reflex sympathetic dystrophy.” CRPS Type I used to be called reflex sympathetic dystrophy. CRPS Type II used to be called Causalgia.

In a patient with clinical findings of CRPS, the distinction between Type I and Type II CRPS depends on the physician’s assessment of the nature of the injury underlying the CRPS. In many situations, the distinction is obvious – if CRPS onsets following an ankle sprain or a fracture of the hand, it is Type I CRPS. If CRPS onsets following a gunshot wound that severely injures the median nerve, it is Type II CRPS.

Complex Regional Pain Syndrome Symptoms


  • Symptoms develop following injury (usually symptoms begin within 2 months post injury).
  • Onset is in a single extremity.
  • Burning pain.
  • Hyperalgesia or allodynia (allodynia means pain elicited by stimuli that normally are not painful, i.e., a patient reports severe pain in response to gentle stroking of the skin.).
  • Swelling.
  • Asymmetry or instability of temperature or color.
  • Asymmetry or instability of sweating.
  • Trophic changes of skin, nails, hair.


Complex Regional Pain Syndrome Diagnosis

A clinical evaluation by physician.

A three-phase bone scan with characteristic pattern of abnormality. (NOTE – An abnormal bone scan is not required for the diagnosis of CRPS.)

Diagnostic sympathetic block.

Complex Regional Pain Syndrome Treatment

It is crucial that pain control interventions be linked closely with physical/occupational therapy. Physical or occupational therapy sessions are scheduled as soon as possible after a sympathetic block. The interval between block and therapy should always be less than 24-hours. In general, physical/occupational therapy should be directed toward activation and desensitization in the affected limb.

Clinicians use a variety of medications to control pain in patients with CRPS. These include alpha adrenergic blockers, corticosteroids, antidepressants, anti-seizure medications, mexiletine and opiates.