Diagnosis of Complex Regional Pain Syndrome
Diagnosis of complex regional pain syndrome is primarily clinical, relying on a detailed history, symptom presentation, and physical examination. Because there is no single definitive test, diagnosing complex regional pain syndrome can be challenging and often involves ruling out other potential conditions with similar symptoms.
The most widely accepted criteria for diagnosing CRPS are known as the Budapest Criteria, which require:
Continuing pain that is disproportionate to any known inciting event
At least one symptom in three of the four categories: sensory, vasomotor, sudomotor/oedema, and motor/trophic
At least one sign at the time of evaluation in two or more of the same categories
Assessment and Examination
Doctors will examine:
Skin temperature and colour changes
Swelling and sweating patterns
Sensitivity to touch or movement
Range of motion and motor function
A thorough history is also essential. Patients are asked about the onset, severity, and progression of symptoms, as well as any recent injuries, surgeries, or immobilisations.
Diagnostic Tests | Diagnosis of Complex Regional Pain Syndrome
While no test can confirm CRPS definitively, additional investigations help exclude other causes:
X-rays or bone scans: May show changes in bone density or structure
MRI or ultrasound: Helps assess tissue changes and swelling
Thermography: Measures skin temperature differences between limbs
Nerve conduction studies: Rule out other nerve conditions
In cases of suspected CRPS-II, which involves known nerve damage, nerve studies may help determine the extent of the injury.
Because CRPS can mimic other conditions such as neuropathies, arthritis, or infection, a multi-disciplinary approach is often beneficial, involving pain specialists, neurologists, rheumatologists, and physiotherapists.
In summary, the diagnosis requires careful clinical judgement and a process of exclusion. Early recognition is vital, as delayed diagnosis can lead to worse outcomes and more entrenched symptoms.
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