Synopsis
Diagnose complex regional pain syndrome clinically without missing dangerous mimics, then restore function through early coordinated rehabilitation, pain treatment and psychologically informed support.
- CRPS is continuing regional pain disproportionate to the inciting event with sensory, vasomotor, sudomotor or oedema and motor or trophic abnormalities.
- Use Budapest criteria: continuing disproportionate pain, symptoms in at least three of four categories, signs on examination in at least two categories and no better diagnosis.
- First-line assessment is clinical examination and exclusion of dangerous mimics; no blood test, MRI or bone scan confirms CRPS.
- Type I has no confirmed major nerve injury and type II follows nerve injury, but the rehabilitation principles are similar.
- Refer early to physiotherapy or occupational therapy and pain services when symptoms are persistent, severe, diagnostically uncertain or function is deteriorating.
- Management combines clear explanation, desensitisation, graded functional use, oedema and range work, laterality or motor imagery where appropriate and psychological strategies for living with pain.
- For neuropathic pain, amitriptyline may start at 10 to 25 mg orally in the evening and increase by 10 to 25 mg every 3 to 7 days toward 25 to 75 mg daily as tolerated; review function and adverse effects.
- Pregabalin may start at a total 150 mg daily in two or three divided doses, rise to 300 mg after 3 to 7 days and at most 600 mg after another 7 days, with renal adjustment and a discontinuation plan.
Key red flags
Pain on passive stretch, tense compartments or rapidly escalating analgesic need after injury or casting requires emergency compartment-syndrome assessment.
Fever, wound discharge, spreading erythema, joint effusion or systemic illness raises concern for infection and needs prompt source investigation.
A cool pale pulseless limb, acute motor loss or worsening perfusion needs immediate vascular and orthopaedic assessment.
Scalding pain confined to one named nerve distribution after surgery or trauma may indicate acute nerve injury or entrapment requiring urgent surgical review.
New whole-limb swelling, venous tenderness, chest pain or breathlessness requires DVT or PE assessment rather than a CRPS assumption.
Suicidal thoughts, severe depression, medication dependence or catastrophic functional collapse requires urgent mental-health or specialist pain support alongside physical care.
Investigation priorities
Establish the required pain, symptom and observed-sign pattern while testing whether another diagnosis is better.
Management branches
Regional pain and autonomic or motor change persist beyond the expected injury course.
- Repeat wound, joint, fixation, compartment, vascular and named-nerve examination before applying a pain label.
- Document Budapest symptoms and observed signs in each of the four categories.
- Order only targeted tests for infection, vascular, structural or nerve alternatives.
- Explain the working diagnosis and arrange early therapy and pain follow-up without waiting for a confirmatory scan.