Calcific Uraemic Arteriolopathy (Calciphyalxis)
🩸 Calcific uraemic arteriolopathy (CUA / Calciphylaxis) is a rare, devastating syndrome.
It causes painful necrotic skin lesions due to vascular calcification in ESRF.
⚠️ Mortality in chronic renal disease is reported to be 60–80%.
ℹ️ About
- Rare disorder characterised by diffuse calcium deposition in small arterioles. 🧬
- Vascular calcification → ischemia → painful necrosis of skin & soft tissue.
- Most often seen in end-stage renal failure (ESRF) patients on dialysis.
⚠️ Risk Factors
- 💊 Warfarin (when cause, prognosis is often better; recovery in most reported cases).
- 💊 Calcium-based phosphate binders (calcitriol, calcium carbonate).
- 💧 ESRF (especially on dialysis).
- ⬆️ High phosphate, secondary hyperparathyroidism.
- Female sex, obesity, diabetes, liver disease (reported associations).
🧬 Aetiology / Pathophysiology
- Calcification & thrombosis of dermal/subcutaneous arterioles → skin & fat necrosis.
- Not always driven by uncontrolled hyperparathyroidism alone.
- Often multifactorial: Ca-P product imbalance, uremia, medications (warfarin, Vit D analogues).
👩⚕️ Clinical
- Extremely painful, tender necrotic ulcers. ⚡
- Sites: legs, thighs, abdomen, buttocks, genitals.
- Eschar with surrounding violaceous livedo-like plaques. 🔴🟣
- Systemic involvement possible: GI, lung, muscle, eye, brain (rare).
🔎 Investigations
- 🧪 U&E: ESRF features.
- ⬆️ PTH.
- ⬆️ Phosphate.
- ⬆️ CRP / ESR (inflammatory response, risk of infection/sepsis).
- Skin biopsy (risk of poor healing) → vascular calcification & thrombosis.
📊 Prognosis: Mortality very high (median survival < 1 year).
👉 However, calciphylaxis from warfarin has a far better outlook (15/18 cases recovered).
💊 Management
- ⚕️ Supportive: Pain control (often requires opioids), meticulous wound care, infection monitoring.
- 💊 Switch therapy: Stop warfarin if implicated. Use non-calcium PO₄ binders (Sevelamer, lanthanum).
Calcimimetics (cinacalcet) can lower PTH without raising calcium.
- 💉 Sodium thiosulfate (STS): IV infusions used experimentally → chelates calcium, improves pain/lesions.
- 🌬️ Hyperbaric oxygen: Reported benefit in wound healing in selected patients.
- 💧 Dialysis optimisation: intensify haemodialysis frequency (e.g. 4×/week).
- 🩺 Early palliative involvement for pain relief & quality-of-life planning if prognosis poor.
📚 References
💡 Tx pearls (exam/ward):
✅ Calcimimetics (replace Vit D analogues) ↓PTH w/o ↑Ca.
✅ Sodium thiosulfate (STS).
✅ Increase HD intensity (e.g. 4x/week).
✅ Aggressive pain & wound care.
✅ Monitor closely for sepsis/infection → leading cause of death.