Calcific Uraemic Arteriolopathy (Calciphyalxis)
๐ฉธ Calcific uraemic arteriolopathy (CUA / Calciphylaxis) is a rare, devastating syndrome.
It causes painful necrotic skin lesions due to vascular calcification in ESRF.
โ ๏ธ Mortality in chronic renal disease is reported to be 60โ80%.
โน๏ธ About
- Rare disorder characterised by diffuse calcium deposition in small arterioles. ๐งฌ
- Vascular calcification โ ischemia โ painful necrosis of skin & soft tissue.
- Most often seen in end-stage renal failure (ESRF) patients on dialysis.
โ ๏ธ Risk Factors
- ๐ Warfarin (when cause, prognosis is often better; recovery in most reported cases).
- ๐ Calcium-based phosphate binders (calcitriol, calcium carbonate).
- ๐ง ESRF (especially on dialysis).
- โฌ๏ธ High phosphate, secondary hyperparathyroidism.
- Female sex, obesity, diabetes, liver disease (reported associations).
๐งฌ Aetiology / Pathophysiology
- Calcification & thrombosis of dermal/subcutaneous arterioles โ skin & fat necrosis.
- Not always driven by uncontrolled hyperparathyroidism alone.
- Often multifactorial: Ca-P product imbalance, uremia, medications (warfarin, Vit D analogues).
๐ฉโโ๏ธ Clinical
- Extremely painful, tender necrotic ulcers. โก
- Sites: legs, thighs, abdomen, buttocks, genitals.
- Eschar with surrounding violaceous livedo-like plaques. ๐ด๐ฃ
- Systemic involvement possible: GI, lung, muscle, eye, brain (rare).
๐ Investigations
- ๐งช U&E: ESRF features.
- โฌ๏ธ PTH.
- โฌ๏ธ Phosphate.
- โฌ๏ธ CRP / ESR (inflammatory response, risk of infection/sepsis).
- Skin biopsy (risk of poor healing) โ vascular calcification & thrombosis.
๐ Prognosis: Mortality very high (median survival < 1 year).
๐ However, calciphylaxis from warfarin has a far better outlook (15/18 cases recovered).
๐ Management
- โ๏ธ Supportive: Pain control (often requires opioids), meticulous wound care, infection monitoring.
- ๐ Switch therapy: Stop warfarin if implicated. Use non-calcium POโ binders (Sevelamer, lanthanum).
Calcimimetics (cinacalcet) can lower PTH without raising calcium.
- ๐ Sodium thiosulfate (STS): IV infusions used experimentally โ chelates calcium, improves pain/lesions.
- ๐ฌ๏ธ Hyperbaric oxygen: Reported benefit in wound healing in selected patients.
- ๐ง Dialysis optimisation: intensify haemodialysis frequency (e.g. 4ร/week).
- ๐ฉบ Early palliative involvement for pain relief & quality-of-life planning if prognosis poor.
๐ References
๐ก Tx pearls (exam/ward):
โ
Calcimimetics (replace Vit D analogues) โPTH w/o โCa.
โ
Sodium thiosulfate (STS).
โ
Increase HD intensity (e.g. 4x/week).
โ
Aggressive pain & wound care.
โ
Monitor closely for sepsis/infection โ leading cause of death.