Calciphylaxis is a rare, but serious, kidney complication. The condition causes calcium to build up inside the blood vessels of the fat and skin. Calciphylaxis is also called calcific uremic arteriolopathy. It’s most often seen in people with advanced chronic kidney disease (end-stage renal disease), or people with kidney failure who are on dialysis or have had a kidney transplant. In dialysis, a machine filters and purifies the blood because the kidneys are unable to do so on their own.
Calciphylaxis results in the formation of very painful skin lesions. It often causes serious infections that can be fatal.
What are the symptoms of calciphylaxis?
The main symptom of calciphylaxis includes skin lesions on the lower limbs or areas with higher fat content, such as the breasts, buttocks, and abdomen. The lesions eventually progress to extremely painful ulcers or nodules. These lesions are very difficult to heal.
A person with calciphylaxis may have higher than normal levels of calcium (hypercalcemia) and phosphate (hyperphosphatemia) in the blood. They may also have symptoms of hyperparathyroidism. Hyperparathyroidism occurs when the parathyroid glands make too much parathyroid hormone (PTH). PTH helps regulate the levels of calcium, vitamin D, and phosphorus in your bones and blood.
Symptoms of calciphylaxis include:
- body aches
How does calciphylaxis affect the skin?
What causes calciphylaxis?
Calciphylaxis occurs from a buildup of calcium inside the blood vessels. The exact cause for this buildup isn’t clear. There are likely multiple processes at play. One contributing factor may be problems with the metabolism of minerals and hormones, including:
- parathyroid hormone (PTH)
PTH is responsible for normalizing the levels of calcium, vitamin D, and phosphorus in the bones and blood.
The disruption in mineral metabolism is thought to be a result of kidney disease, but the exact mechanism isn’t truly understood. This is especially true since the condition can occur in people with normal kidney function. More research is needed to better understand the condition.
Who is at risk for calciphylaxis?
People with advanced kidney disease are at the highest risk of having calciphylaxis. According to a study published by São Paulo State University, calciphylaxis occurs in roughly 1 to 4.5 percent of people on dialysis. It’s considered a rare condition, but it may become more common as the number of people on dialysis increases.
Calciphylaxis is more commonly reported in people receiving dialysis who also:
- are obese
- are taking systemic corticosteroids
- are taking warfarin (Coumadin) to treat or prevent blood clots
- are using calcium supplements containing phosphate binders
- have liver disease
- have diabetes
Although calciphylaxis is mostly reported in people with advanced kidney disease, it’s sometimes diagnosed in people with normal kidney function who have the following conditions:
- inflammatory bowel disease
- primary hyperparathyroidism
- autoimmune conditions such as systemic lupus erythematosus (lupus), Crohn’s disease, or rheumatoid arthritis
- hypercoagulable conditions such as protein C and protein S deficiency
- alcoholic liver disease
Calciphylaxis is most commonly reported in people over the age of 50. And, according to a study published by the American Journal of Kidney Diseases, calciphylaxis occurs twice as frequently in women than in men.
A doctor might suspect calciphylaxis based on the presence of painful skin lesions and your medical history. They will typically run several tests in order to confirm a diagnosis and rule out other complications of chronic kidney disease. Some of these diagnostic tests may include:
- a skin biopsy
- blood tests for levels of calcium, phosphorous, alkaline phosphatase, parathyroid hormone, and 25-hydroxyvitamin D
- liver function blood tests
- kidney function tests
- tests to evaluate infections, such as a complete blood count and blood culture tests
How is calciphylaxis treated?
At the moment, there isn’t an effective treatment available for calciphylaxis. Current treatment is focused on caring for the skin lesions, preventing infections, and correcting the calcium and phosphorous concentrations in the blood.
Treating the wounds and lesions might include:
- enzymatic debriding agents
- hydrocolloid or hydrogel dressings
- systemic antibiotics
- hyperbaric oxygen therapy
Medications may be prescribed to treat the wounds and to correct abnormal calcium and phosphorus concentration in the blood. These may include:
- intravenous sodium thiosulfate, a chelating agent for calcium and iron
- cinacalcet (Sensipar), a drug used to treat high levels of calcium in the blood of people with certain parathyroid gland problems or chronic kidney disease
A clinical trial by Massachusetts General Hospital is currently evaluating whether vitamin K supplements can be used to treat calciphylaxis.
If your calcium and phosphorous levels can’t be controlled with medication, you may need surgery to remove one or more parathyroid glands. This surgery is called parathyroidectomy. Your doctor may also recommend increasing your dialysis sessions.
Since calciphylaxis is often debilitating, you may also need nutritional and psychological support and pain management.
What is the outlook?
Calciphylaxis is often a fatal condition. According to a study published by the American Journal of Kidney Diseases, people with Calciphylaxis have a one-year survival rate of less than 46 percent. Death is usually a result of complications, such as infections and sepsis. Sepsis is a life-threatening infection of the blood.
Recovery is possible, and early diagnosis and treatment can lead to better outcomes. The survival rate is expected to improve as more is learned about the condition.