Calciphylaxis (kal-sih-fuh-LAK-sis) is a serious, uncommon disease in which calcium accumulates in small blood vessels of the fat and skin tissues.

Calciphylaxis causes blood clots, painful skin ulcers and may cause serious infections that can lead to death. People who have calciphylaxis usually have kidney failure and are on dialysis or have had a kidney transplant. The condition can also occur in people without kidney disease.


Signs and symptoms of calciphylaxis include:

  • Large purple net-like patterns on skin
  • Deep, very painful lumps that ulcerate creating open sores with black-brown crust that fails to heal — typically in skin areas with high fat content, such as the stomach and thigh, although they can occur anywhere
  • Infections from wounds that don't heal


The exact cause of calciphylaxis is unknown, but recent studies have revealed that most people with the condition have abnormalities in blood-clotting factors. Blood-clotting factors are substances in your blood that help stop bleeding. These abnormalities can lead to small blood clots forming more often than they normally would.

In addition, people with calciphylaxis have an imbalance in the metabolism of calcium. This causes calcium to be deposited in the smallest parts of the arteries (arterioles), which eventually leads to the formation of blood clots in the arterioles. Blood clots can cause fat tissues and skin to be deprived of oxygen and nourishment.

Risk factors

Calciphylaxis most commonly affects people who have end-stage kidney failure. Possible risk factors include:

  • Being female
  • Obesity
  • Diabetes
  • Abnormalities in blood-clotting factors
  • Long-term dialysis and sometimes kidney transplantation
  • An imbalance of calcium, phosphorus and aluminum in the body
  • Some medications, such as warfarin (Coumadin, Jantoven), calcium-binding agents or corticosteroids
  • An overproduction of parathyroid hormone (PTH), which regulates the level of calcium and phosphorus in the body — a condition known as hyperparathyroidism
  • Uremia, a toxic condition in which substances normally eliminated in the urine — such as calcium and phosphorus — build up in the body


Complications of calciphylaxis include:

  • Severe pain
  • Large, deep, nonhealing ulcers
  • Blood infections
  • Death, usually due to infection and multiorgan failure

Typically, the outlook for people with calciphylaxis isn't hopeful. Early detection and treatment is very important in helping to prevent serious infections.

Calciphylaxis care at Mayo Clinic

Sept. 03, 2022
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