Definition
Complex regional pain syndrome (CRPS) is a pain condition characterised by continuing regional pain that is disproportionate in time or degree to the usual course of any known trauma or other lesion. It is associated with sensory, vasomotor, sudomotor and motor or trophic disturbance.
Types
- CRPS type I — no confirmed nerve injury
- CRPS type II — associated with a confirmed nerve injury
Clinical features
Sensory
- Severe pain
- Hyperalgesia
- Allodynia
Vasomotor
- Temperature asymmetry
- Skin colour change or asymmetry
Sudomotor / oedema
- Swelling
- Sweating change or asymmetry
Motor / trophic
- Stiffness
- Weakness
- Tremor or dystonia
- Reduced range of motion
- Hair, nail or skin trophic change
Diagnosis
Diagnosis is clinical and usually based on the Budapest criteria.
The patient should have:
- continuing pain disproportionate to the inciting event
- at least one symptom in three of the four categories above
- at least one sign at examination in two or more categories
- no other diagnosis that better explains the presentation
Investigations
Investigations are used mainly to exclude other causes. Depending on the clinical situation, consider:
- plain radiographs
- MRI
- inflammatory markers
- nerve studies if another neuropathic diagnosis is suspected
Management
Management is multidisciplinary and early treatment is important.
Core treatment
- explanation and reassurance
- physiotherapy and graded mobilisation
- occupational therapy and desensitisation
- analgesia according to pain type and severity
Additional options
- neuropathic pain medication
- short course of steroids in selected early cases
- bisphosphonates in selected patients
- pain specialist referral for resistant cases
- psychological support where needed
Orthopaedic principles
- avoid unnecessary immobilisation
- encourage function
- treat fractures or surgical problems appropriately, but do not overlook CRPS when pain and stiffness are disproportionate
Diagram
