🩺 Complex Regional Pain Syndrome (CRPS)
CRPS is a chronic pain disorder, usually affecting a limb after trauma or surgery.
It is characterised by disproportionate pain plus sensory, motor, autonomic and trophic changes.
Early recognition and rehabilitation are vital to prevent long-term disability.
📖 Types
- CRPS I – no identifiable nerve injury (≈90% cases).
- CRPS II – clear peripheral nerve injury.
🧬 Pathophysiology
- Peripheral & central sensitisation → exaggerated pain signalling.
- Neurogenic inflammation (substance P, CGRP, cytokines).
- Autonomic dysregulation → vasomotor + sweating abnormalities.
- Cortical reorganisation & psychological contributors.
🩺 Clinical Features
- Burning, severe pain out of proportion to injury.
- Allodynia, hyperalgesia.
- Colour/temperature asymmetry, swelling, sweating changes.
- Motor: weakness, stiffness, tremor, dystonia.
- Trophic: altered hair, nails, thin shiny skin.
📊 Diagnosis – Budapest Criteria
- Continuing pain disproportionate to inciting event.
- ≥3 symptom categories + ≥2 sign categories (sensory, vasomotor, sudomotor/oedema, motor/trophic).
- No better alternative explanation.
🛠️ Management
- Education & reassurance – explain benign but disabling nature.
- Physiotherapy – early mobilisation, mirror therapy, graded motor imagery.
- Psychological support – CBT, coping strategies.
- Pharmacology – neuropathic agents (gabapentin, amitriptyline), bisphosphonates, short steroid courses, IV ketamine/lidocaine in select cases.
- Interventions – sympathetic blocks, spinal cord or dorsal root ganglion stimulation in refractory cases.
📈 Prognosis
- Best outcomes with early diagnosis and active rehab.
- Warm/early CRPS is more reversible than chronic “cold” phase.
- Many improve within 12 months, but chronic cases may persist and cause severe disability.
📌 Summary Table
| Feature | Key Points |
|---|
| Nature | Chronic pain syndrome, sensory + autonomic + trophic changes |
| Types | Type I (no nerve injury), Type II (nerve injury) |
| Diagnosis | Clinical, Budapest Criteria |
| Management | Multidisciplinary: physio, psychology, neuropathic meds, blocks, neurostimulation |
| Prognosis | Early intervention crucial; variable long-term outcomes |
💡 Clinical Pearls
- Always suspect CRPS in persistent, disproportionate post-trauma pain.
- Do not immobilise – early mobilisation improves outcomes.
- Consider bisphosphonates if pain and bone scan activity present.
- Cold CRPS = poorer prognosis, emphasise early referral to pain specialists.
📚 References
🩺 Case Examples - Complex Regional Pain Syndrome (CRPS)
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Case 1 (CRPS type I - post-fracture):
A 48-year-old woman presents with severe burning pain, swelling, and hypersensitivity in her right wrist, 6 weeks after a Colles’ fracture treated conservatively. The skin is shiny and red, with increased sweating, and she cannot tolerate light touch (allodynia). X-ray shows patchy demineralisation but no new fracture. Diagnosis: CRPS type I (no definable nerve injury, post-fracture). Management involves early physiotherapy, desensitisation exercises, neuropathic analgesics (e.g. gabapentin), and referral to a pain clinic.
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Case 2 (CRPS type II - post-nerve injury):
A 35-year-old man develops severe stabbing pain, oedema, and bluish discolouration of the left foot after a laceration with confirmed tibial nerve injury. The limb is cool with trophic changes (brittle nails, hair loss). Symptoms are disproportionate to the original injury and limit weight-bearing. Diagnosis: CRPS type II (causalgia - following nerve damage). Management includes neuropathic analgesia, graded motor imagery, physiotherapy, and sympathetic nerve block under specialist pain services.
