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Health condition · Clinically reviewed

Calciphylaxis, a rare, painful and serious dialysis complication - and what an MDT can do about it.

Calcific uraemic arteriolopathy is uncommon but life-threatening. Early recognition, sodium thiosulphate, wound care and pain control give people the best chance.

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Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against Renal Association, KDIGO, BAD and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK practice including sodium thiosulphate, non-calcium binders and MDT-led wound care.

Key facts

Calciphylaxis at a glance.

The essentials, in plain English - what it is, who it affects, and the pillars of UK treatment.

  • What it is

    Calcification of small arterioles in the subcutaneous fat and dermis, leading to ischaemic skin necrosis, painful ulcers and a high mortality.

  • Also known as

    Calcific uraemic arteriolopathy (CUA). Non-uraemic forms occur in liver disease, malignancy and hyperparathyroidism.

  • Who gets it

    Predominantly people with end-stage renal disease on dialysis, at roughly 1 to 4 per cent of the dialysis population each year.

  • Why it matters

    One-year mortality is approximately 50 to 80 per cent, mostly from sepsis. Early recognition and MDT care matter.

  • Mainstay drug

    Sodium thiosulphate 25 g intravenously three times a week during or after dialysis is the evidence-based mainstay.

  • Bone metabolism

    Lowering the calcium and phosphate product, switching to non-calcium phosphate binders and treating hyperparathyroidism.

Why this guide matters

Rare, serious - and time-critical.

Because calciphylaxis is uncommon, it is easily missed. The three points below shape everything else on this page.

  • High suspicion saves lives

    Painful violaceous skin lesions in a dialysis patient are calciphylaxis until proven otherwise. Early biopsy and MDT input change the trajectory.

  • Sodium thiosulphate is the mainstay

    IV sodium thiosulphate given with dialysis is the best-evidenced medical treatment for reducing calcification and easing pain.

  • Care is multidisciplinary

    Nephrology, dermatology, wound care, pain, palliative care and plastics working together produce the best outcomes.

How the diagnosis is made

From painful skin to a coordinated plan.

The steps a UK renal team and dermatologist will normally follow, in order - so you know what to expect and why.

  1. 01

    Recognising

    High clinical suspicion

    Painful violaceous mottled skin lesions in a dialysis patient should prompt urgent nephrology and dermatology review.

  2. 02

    Recognising

    Full history and drug review

    Warfarin use, calcium-based binders, active vitamin D, recent subcutaneous injections and autoimmune disease all count.

  3. 03

    Recognising

    Structured skin examination

    Livedo racemosa, indurated plaques, black eschar and non-healing ulcers on proximal (thighs, abdomen, buttocks) or distal sites.

  4. 04

    Confirming

    Deep incisional skin biopsy

    Gold standard when safe. Includes subcutaneous fat and shows small-vessel calcification, intimal proliferation, microthrombi and panniculitis. Avoid punch biopsy where possible.

  5. 05

    Confirming

    Bloods and coagulation

    Calcium, phosphate, PTH, alkaline phosphatase, vitamin D, albumin, coagulation, thrombophilia, antiphospholipid and autoimmune screen.

  6. 06

    Confirming

    Imaging and infection workup

    Plain X-ray or mammography can show vascular calcification. Bone scan may show soft tissue uptake. Wound swab and blood cultures if infected.

  7. 07

    Coordinating

    MDT coordination

    Nephrology, dermatology, tissue viability, pain, palliative care and plastic surgery agree the plan together.

Typical timeline: days to weeks from first lesion to a confirmed diagnosis and MDT plan.

Symptoms

What calciphylaxis actually looks like.

Severe pain, mottled purple patches and non-healing ulcers, often in fatty sites. Distribution matters for prognosis.

  • Painful violaceous patches

    Reticulate mottled purple discoloration, often exquisitely painful and out of proportion to what you see.

  • Livedo racemosa

    A broken, net-like violaceous pattern that can be an early sign before frank ulceration develops.

  • Indurated plaques

    Firm, tender, board-like areas of skin as the underlying fat becomes calcified and inflamed.

  • Black necrotic eschar

    Dry, black, adherent tissue over ischaemic skin, often with a red or purple rim.

  • Non-healing ulcers

    Deep, punched-out ulcers that fail to granulate and frequently become secondarily infected.

  • Proximal distribution

    Thighs, abdomen and buttocks. Adipose-rich sites, and a marker of poorer prognosis.

  • Distal distribution

    Calves, ankles and digits. Generally a better prognosis than proximal disease but still serious.

  • Red flag - sepsis

    Fever, rigors, hypotension or spreading cellulitis around a lesion is a medical emergency.

Treatment

How calciphylaxis is treated in the UK.

A multidisciplinary approach centred on sodium thiosulphate, careful wound care, bone-mineral optimisation and specialist pain management.

  • MDT specialist care

    Nephrology, dermatology, tissue viability, pain, palliative care and plastic surgery together. Care in specialist centres improves outcomes.

  • Sodium thiosulphate

    The evidence-based mainstay. Typically 25 g intravenously three times a week during or after dialysis, reducing calcium deposition and pain.

  • Wound care and debridement

    Careful surgical debridement where appropriate, tissue viability input, moist wound care and prompt antibiotics for infection.

  • Optimise bone mineral metabolism

    Non-calcium phosphate binders (sevelamer, lanthanum), cinacalcet or etelcalcetide, and parathyroidectomy for severe hyperparathyroidism.

  • Dialysis optimisation

    Consider daily or nocturnal dialysis, low-calcium dialysate and gentler ultrafiltration to protect the skin microcirculation.

  • Stop warfarin

    Switch to an alternative anticoagulant such as low molecular weight heparin or, cautiously, apixaban. Vitamin K supplementation is discussed but remains debated.

  • Pain management

    Opioids, ketamine, methadone and intrathecal analgesia via specialist palliative pain teams. Pain is severe and central to the plan.

  • Adjuncts

    Bisphosphonates such as pamidronate, vitamin K supplementation, magnesium and hyperbaric oxygen (see /treatments/hyperbaric-oxygen-therapy/) are used case by case.

What this guide is based on

The sources behind every claim on this page.

UK renal and dermatology guidance and international consensus, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your renal team and dermatologist know your history and can tell you which parts apply to you. If in doubt, get seen urgently.

  • UK Kidney Association (Renal Association). Guidance on calciphylaxis and CKD-MBD.

  • KDIGO. Clinical Practice Guideline for the Diagnosis, Evaluation, Prevention, and Treatment of CKD-MBD.

  • British Association of Dermatologists (BAD). Patient leaflets on calciphylaxis.

  • Nigwekar SU et al. Calciphylaxis. New England Journal of Medicine review.

Red flags

When calciphylaxis needs urgent attention.

Calciphylaxis is an emergency. These are the features that mean same-day specialist review, not next-week clinic.

  • Rapidly spreading necrosis

    Fast progression of black eschar or new lesions is a surgical and nephrology emergency and needs same-day specialist review.

  • Sepsis

    Fever, rigors, hypotension or confusion around known lesions - treat as neutropenic-style sepsis until proven otherwise.

  • Uncontrolled pain

    Pain out of proportion to visible skin change is a hallmark. Escalate early to specialist palliative pain services.

  • Proximal truncal disease

    Lesions on thighs, abdomen or buttocks carry a worse prognosis and warrant urgent MDT input.

  • New warfarin exposure

    A recent start or dose change of warfarin in a dialysis patient with new skin lesions should raise immediate suspicion.

  • Severe hyperparathyroidism

    Very high PTH with rising calcium and phosphate needs urgent bone-mineral optimisation and consideration of parathyroidectomy.

  • Non-healing ulcer in ESRD

    Any ulcer in an adipose site in a dialysis patient that fails to heal deserves a calciphylaxis workup.

  • Bleeding or gangrene of digit

    Distal digital gangrene needs vascular and plastic surgery review alongside nephrology.

  • Psychological distress

    Pain, disfigurement and prognosis take a heavy toll. Early psychology and palliative care support is essential.

Living with it

A serious diagnosis, carried by a team.

Four things that make the biggest difference day to day - staying with your MDT, asking for enough pain relief, protecting your bone metabolism and using UK kidney charities for support.

A quiet reminder

Honest conversations belong here too.

With a guarded prognosis, palliative care is not the end of treatment. It sits alongside active care and helps you focus on what matters most.

  1. 01 Team

    Stay with your MDT

    Care is best delivered by a coordinated nephrology, dermatology, wound-care and palliative team. Keep every appointment.

  2. 02 Pain

    Ask for enough pain relief

    Calciphylaxis pain is severe. Specialist palliative pain teams can help - opioids, ketamine and intrathecal options all have a place.

  3. 03 Dialysis

    Protect your bone metabolism

    Take non-calcium binders as prescribed, keep dialysis sessions and blood tests, and avoid over-the-counter calcium and vitamin D unless advised.

  4. 04 Support

    Lean on Kidney Care UK

    Practical, emotional and financial support is available. You do not have to face this alone.

Frequently asked

Everything we get asked about calciphylaxis.

Quick answers on causes, diagnosis, treatment and prognosis.

  • What is calciphylaxis?

    Calciphylaxis, also called calcific uraemic arteriolopathy, is a rare and life-threatening condition where small arteries in the fat and skin become calcified. This causes reduced blood flow, painful skin lesions and non-healing ulcers, with a high risk of infection and death.

  • Who is most at risk?

    People with end-stage kidney disease on dialysis are at highest risk, particularly if they are female, obese, diabetic, on warfarin, or have high calcium, phosphate or parathyroid hormone levels. It can also occur without kidney failure in liver disease, some cancers and autoimmune conditions.

  • How is it diagnosed?

    Diagnosis is based on a high level of clinical suspicion in a dialysis patient with painful violaceous skin lesions, supported by a deep incisional skin biopsy that includes subcutaneous fat. Blood tests, imaging and infection screens complete the workup.

  • How is calciphylaxis treated in the UK?

    Care is delivered by a multidisciplinary team. Sodium thiosulphate is the mainstay drug. Treatment also focuses on bone mineral metabolism (non-calcium binders, cinacalcet, sometimes parathyroidectomy), wound care, pain control, dialysis optimisation and stopping warfarin.

  • Why is warfarin stopped?

    Warfarin blocks vitamin K, which is needed for matrix Gla protein, a natural inhibitor of vascular calcification. In calciphylaxis, warfarin is switched to an alternative anticoagulant such as low molecular weight heparin or, cautiously, a direct oral anticoagulant.

  • What is the prognosis?

    Calciphylaxis carries a serious prognosis, with one-year mortality of roughly 50 to 80 per cent, mostly from infection. Early diagnosis, MDT care and palliative support all improve outcomes and quality of life, and honest conversations about goals of care are an important part of treatment.

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