Makindo Medical Notes

🩸 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

• Calcific uraemic arteriolopathy (calciphylaxis): data from a large nationwide registry

💡 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.