Complex regional pain syndrome is a chronic pain condition, usually in an arm or leg, where pain is far out of proportion to the original injury, such as a fracture or surgery. It brings changes in sensation, blood flow, sweating, swelling and movement of the limb.
Key symptoms
- Constant burning pain, worse than expected from the injury
- Pain with light touch (allodynia)
- Swelling, color and temperature changes of the limb
- Stiffness, weakness or tremor
- Changes in hair, nails or skin
What you find on exam
- Compare both limbs for temperature, color, sweating and swelling
- Light touch and pinprick for allodynia and hyperalgesia
- Range of motion and strength
- Trophic changes of skin, hair and nails
Tests
- Diagnosis by the Budapest clinical criteria
- X-ray may show patchy bone loss
- Three-phase bone scan in uncertain cases
- Tests to exclude infection, clots or nerve injury
Treatment basics
- Early physical and occupational therapy, graded motor imagery and mirror therapy
- Medicines such as gabapentin, amitriptyline, NSAIDs or a short prednisone course
- Bisphosphonates in early disease
- Psychological support and pain specialist care; sympathetic block or spinal cord stimulation if refractory
Red flags
- Spreading pain with rapid loss of function
- Fever, redness and a hot limb (infection) or calf swelling (clot)
- Depression or thoughts of suicide from chronic pain
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Related guides
Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.