Patient Information

Calciphylaxis is a serious condition that can occur in people chronic kidney disease; it is most commonly seen in people receiving dialysis but remains very rare with approximately one case diagnosed in every 600 people, having dialysis, per year. It can sometimes occur in people that do not have kidney disease. It happens when small blood vessels in and around the skin become blocked by a build-up of calcium products; this is referred to as calcification. The blockage (calcification) leads to a lack of blood supply, preventing adequate oxygen from getting to the skin. This causes the development of painful skin ulcers which can lead to serious infections.


The exact cause of calciphylaxis remains unknown; we do not know why some people get the condition and others do not. Possible risk factors (things that may contribute to the development of calciphylaxis) are considered to be:

  • Warfarin use (a blood thinning medication)
  • Long-term dialysis
  • High blood levels of calcium, and/or phosphate
  • Being overweight

The trigger for the disease is not known but may include local injury; for example, people can report their calciphylaxis started with a flee bite, cut or graze to the area.

There is no diagnostic test for calciphylaxis. Diagnosis is made by clinical examination. Sometimes a skin biopsy can be taken (a small sample of skin is removed and tested) to check for evidence of calcification but this isn’t always necessary.

Calciphylaxis commonly affects the soft tissues of the body around the abdomen and legs but can affect any area of the body including (but not limited to) the torso, breast and external genitalia. The main symptom (from the ulcers) is pain which can be extreme. If the ulcers become infected then this can result in hospital admission.  People can feel weak and unwell; this may be caused by a combination of factors including the pain, possibly infection, along with the burden of undergoing the treatments. Whilst some people make a good recovery, sadly around 5 out of 10 people die within a year of diagnosis.

There is no specific treatment as yet that is shown to work. Your doctor will try and individualise your care to reduce your risk factors. This may include improving your calcium and phosphate levels or stopping medications such as warfarin. They may also consider experimental treatments or clinical trials where available.

To be added

The rarity of the condition has limited the ability to do large research studies.


  1. The UK Calciphylaxis Study is currently underway. This study aims to find out:
  • What the natural history and the development of the disease is (how calciphylaxis starts, the location of the ulcers, how well the ulcers heal and if the patient recovers)
  • What risk factors are associated with development and progression of calciphylaxis?
  • Which treatments offer a favourable outcome?

This study is being led by Professor Smeeta Sinha in Salford.

  1. An international study (BEAT-CALCI) is also underway aiming to determine the best treatment for the condition. The UK are hoping to become involved with this study.


  1. Professor Sinha’s research team are currently developing a research study to investigate and understand patient experiences of calciphylaxis. The hope is this study will identify gaps and better understand patient needs to help health professionals to improve the care and support provided.


  1. The Calciphyx study has recently finished recruitment. This study is investigating whether the investigational drug SNF472 can improve outcomes. The results should be available in 2023.

Calciphylaxis is a rare complication and the information available remains very limited. There is a need for greater awareness and support. If you have been diagnosed with the condition and would be willing to share your story or act a patient representative then please do get in touch with the Rare Renal Team


NICE accredited clinical practice guidelines 

Available here

25th Annual Report

Analyses about the care provided to patients at UK renal centres.

Read the report

2022 UKRR AKI Report

A report on the nationwide collection of AKI warning test scores. 

Read the report