How is complex regional pain syndrome (CRPS) diagnosed?
There’s no specific test that will confirm you have complex regional pain syndrome (CRPS). Doctors mainly base the diagnosis on your symptoms and a physical examination, although tests may be used – sometimes to rule out other conditions:
- An x-ray or bone scan of the affected limb may show thinning of the bone (osteoporosis) or other abnormalities.
- Blood tests may help to rule out infection or autoimmune conditions such as rheumatoid arthritis.
- Magnetic resonance imaging (MRI) scans may help to rule out problems with the bones or other tissues.
- Regional anaesthesia, or blocking of the sympathetic nervous system with a local anaesthetic, is occasionally used as a diagnostic test. If this block eases the pain, then it’s likely that you have CRPS.
The International Association for the Study of Pain have set criteria, called the Budapest criteria, to help with diagnosis. These take into account the following symptoms:
- unusual sensitivity to touch
- differences in skin colour or temperature between the affected limb and the normal one
- swelling or unusual sweating in the affected limb
- reduced range of motion, loss of function, or changes in the hair, skin or nails of the affected limb.
If your GP is in any doubt about the diagnosis you may be referred for a specialist opinion.
Once you've been diagnosed with CRPS it's likely that you'll be referred to a specialist pain clinic for treatment – usually at a local hospital.