General definition of the syndrome

Complex regional pain syndrome describes an array of painful conditions that are characterised by a continuing (spontaneous and/or evoked) regional pain that is seemingly disproportionate in time or degree to the usual course of any known trauma or other lesion. The pain is regional (not in a specific nerve territory or dermatome) and usually has a distal predominance of abnormal sensory, motor, sudomotor, vasomotor, and/or trophic findings. The syndrome shows variable progression over time.

To make the clinical diagnosis, the following criteria must be met:

• Continuing pain, which is disproportionate to any inciting event.
• Must report at least one symptom in all four of the following categories:
  • sensory – reports of hyperaesthesia and/or allodynia
  • vasomotor – reports of temperature asymmetry and/or skin colour changes and/or skin colour asymmetry
  • sudomotor/oedema – reports of oedema and/or sweating changes and/or sweating asymmetry
  • motor/trophic – reports of decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin).
• Must display at least one sign at time of evaluation in two or more of the following categories:
  • sensory – evidence of hyperalgesia (to pinprick) and/or allodynia (to light touch and/or temperature sensation and/or deep somatic pressure and/or joint movement)
  • vasomotor – evidence of temperature asymmetry (> 1 °C) and/or skin colour changes and/or asymmetry
  • sudomotor/oedema – evidence of oedema and/or sweating changes and/or sweating asymmetry
  • motor/trophic – evidence of decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
• There is no other diagnosis that better explains the signs and symptoms.