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.


To determine if you have calciphylaxis, your doctor will review your medical history, assess your symptoms and do a physical exam. Tests may include:

  • Skin biopsy. To diagnose calciphylaxis, your doctor may remove a small tissue sample from an area of affected skin for analysis.
  • Blood tests. Blood samples measure a variety of substances in your blood — calcium, phosphorus, parathyroid hormone, abnormalities in blood-clotting factors, aluminum, urea nitrogen, creatinine and albumin, among others — to help your doctor assess your kidney and liver function.
  • Imaging studies. X-rays may show branch-like calcium deposits in the blood vessels (vascular calcifications) that are common in calciphylaxis and in other advanced kidney diseases.


Multiple interventions are used to treat calciphylaxis, including:

Restoring oxygen and blood flow to the skin

Medication that helps keep your blood from clotting (anticoagulation medication) such as apixaban (Eliquis) will likely be prescribed to restore blood flow to affected tissues.

Hyperbaric oxygen therapy can help to increase oxygen delivery to the affected parts of the body. Or your doctor may use low-dose tissue plasminogen activator (TPA) to dissolve blood clots in the tiny blood vessels of the skin.

Decreasing calcium deposits

  • Dialysis. Your doctor may change your dialysis prescription if you're on kidney dialysis, including the medications used in and the frequency of your dialysis.
  • Changing medications. Your doctor will evaluate your current medications and eliminate potential triggers for calciphylaxis, such as warfarin, corticosteroids or iron, and may modify the amount (dose) of your calcium or vitamin D supplements.
  • Taking medications. A medication called sodium thiosulfate can decrease calcium buildup in the arterioles. It's given intravenously three times a week, usually during dialysis. Your doctor may also recommend a medication called cinacalcet (Sensipar), which can help control parathyroid hormone (PTH). Other medications may be used to improve the balance of calcium and phosphorus.
  • Surgery. If an overactive parathyroid gland (hyperparathyroidism) contributes to abnormal calcium metabolism by producing too much PTH, surgery to remove all or part of the parathyroid glands may be recommended.

Applying intensive wound treatment

For sores to heal, some of the tissue damaged by calciphylaxis may need to be surgically removed (debridement). In some cases, tissue can be removed using other methods, such as wet dressings. Antibiotic treatment is part of treating and preventing wound infection.

You may be offered medication for managing pain due to calciphylaxis or during wound care.

Preparing for an appointment

You may start by seeing your primary care provider. Or, you may be referred to a specialist in skin disorders (dermatologist) or kidney disease (nephrologist).

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do in advance, such as fasting before having a specific test. It's also a good idea to bring a family member or friend with you because it can be difficult to remember all of the information from your appointment.

It's also helpful to make a list of:

  • Your symptoms, including any that seem unrelated to the reason for your appointment
  • Key personal information, including major stresses, recent life changes and family medical history
  • All medications, vitamins or other supplements you take, including the doses
  • Questions to ask your doctor

For calciphylaxis, some basic questions to ask your doctor include:

  • What's likely causing my symptoms?
  • Are there other possible causes for my symptoms?
  • What tests do I need?
  • Is my condition likely temporary or long lasting?
  • What treatment do you recommend?
  • I have other health conditions. How can I best manage these conditions together?
  • Are there any dietary restrictions I need to follow?
  • What's my prognosis?
  • Are there brochures or other printed material I can have? What websites do you recommend?

What to expect from your doctor

Your doctor is likely to ask you several questions, such as:

  • When did your symptoms begin?
  • Have your symptoms been continuous or do they come and go?
  • How severe are your symptoms?
  • Does anything seem to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?

Content From Mayo Clinic Updated: 09/02/2022
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