Calciphylaxis

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at July 27, 2016
StartDiseasesCalciphylaxis

Calcium is typically viewed as a beneficial mineral, but in rare cases, imbalanced calcium levels can lead to severe health problems. Though it can occasionally occur in people with other health conditions, calciphylaxis is most commonly associated with patients who have acute kidney failure. Calciphylaxis, which is also called calcific uremic arteriolopathy (CUA), is a health condition that causes calcification of the arteries. Unfortunately, calciphylaxis tends to have very high mortality rates

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Definition & Facts

Calciphylaxis occurs when calcium and other minerals accumulate in the walls of blood vessels, making them harden and stop working normally. Calciphylaxis is very common among people with late stage renal failure due to chronic kidney disease.

Other health conditions, such as cancer or acute liver failure, may also cause calciphylaxis. Since it is a somewhat rare condition that normally only occurs right before someone succumbs to kidney disease, calciphylaxis remains a condition that is difficult to study and understand.

Symptoms & Complaints

Calcification is normally only supposed to occur in the bones of the body, so when it happens to blood vessels, the symptoms are very severe. The first signs of calciphylaxis tend to occur on the skin, since the tiny arteries along the skin are the first blood vessels to stop functioning due to calcification.

The skin will begin to look mottled, reddened, or spotted, and it can be tender to the touch or slightly stiff. This will progress into star-shaped, purplish lesions that feel itchy, or painful.

As the calciphylaxis continues to worsen, oxygen-rich blood cannot travel to the skin, and the tissue begins to die. This necrosis causes black, ulcerous lesions that are extremely painful, and they most commonly form on the legs, abdomen, groin, and buttocks. These ulcers cannot heal, so they typically become further infected or septic.

These infected ulcers can foster bacteria that travels to the organs, resulting in fatal systemic infections. If a patient does not get any sort of dangerous organ infection, the calciphylaxis will continue to progress throughout the body. Eventually, this can cause a severe form of cardiac calcification, referred to as a "heart of stone," and this results in heart failure.

Causes

The precise mechanism that causes the body to begin depositing calcium in the blood vessels is unknown. However, it is generally known that calciphylaxis is often caused by certain health problems, and it is mostly associated with high phosphate levels and low vitamin D levels.

Calciphylaxis is particularly associated with end stage kidney failure because this health condition keeps the body from properly expelling phosphate. The unnaturally high phosphate levels can build up in the blood and combine with calcium. The process of calciphylaxis in patients with kidney disease is further stimulated by low vitamin D levels, which cause enlarged parathyroid glands that results in high blood calcium levels.

Other health conditions that may cause calciphylaxis are hyperparathyroidism, breast cancer, liver failure, Crohn's disease, lupus, and rheumatoid arthritis. Not every person with these health problems or imbalanced mineral levels gets calciphylaxis, so medical researchers still are unsure of why some patients are more likely to develop calciphylaxis. Risk factors for calciphylaxis include being obese, being female, taking corticosteroids, or having diabetes mellitus.

Diagnosis & Tests

There is no simple test that can diagnose calciphylaxis. Instead, it is generally diagnosed through physical examinations or skin biopsies. Other conditions can also cause slowly worsening skin lesions, so problems like necrotising fasciitis must be ruled out first.

Since calciphylaxis typically happens to patients with kidney failure, physicians treating patients with this disease will be on the lookout for the beginning signs of calciphylaxis. The lesions may start out looking like other skin disorders, but as they take on the signature color, shape, and texture, it is normally evident that a patient has calciphylaxis.

If the diagnosis is still not clear, a deep wedge skin biopsy can confirm the diagnosis. Though this test is rather invasive, it can help a doctor to determine if the arteries in the subcutaneous tissue are blocked with calcium deposits. In rare cases where calciphylaxis has become very advanced without a diagnosis, an X-ray may be able to pick up large areas of vascular calcification

Treatment & Therapy

Unfortunately, calciphylaxis has a roughly 80 percent mortality rate due to the combination of septic skin ulcers and the coexisting health condition that typically causes the calciphylaxis in the first place. Since the main way that calciphylaxis causes death is through septic ulcers, wound care is a very important part of treatment.

The primary goal of calciphylaxis treatment is to prevent infections and relieve pain. Debridement to remove dead tissue is helpful, and antibiotics can assist in preventing the wounds from getting infected. Sometimes, dead tissue removal can require amputation of limbs. Most doctors prescribe opioid pain medications to control the pain that occurs alongside the lesions.

Certain medications may help to control the advancement of calciphylaxis. Cinacalcet may be able to balance calcium and phosphorous levels while reducing levels of parathyroid hormone. Sodium thiosulfate can potentially help to chelate calcium before it deposits in arterial tissue.

In cases where the calciphylaxis seems to primarily be caused by an over functioning parathyroid gland, surgical removal of the gland helps to halt the calcification process. Treating the underlying cause of calciphylaxis with dialysis or a kidney transplant helps to control calciphylaxis greatly.

Prevention & Prophylaxis

Because it has such a high mortality rate, doctors emphasize the importance of calciphylaxis prevention among patients with kidney failure and other health conditions associated with calciphylaxis. Noticing and treating hyperparathyroidism before it gets out of control has high prevention rates among patients with renal failure.

It is important for doctors to carefully control calcium and phosphate levels before calciphylaxis develops. Therefore, patients with kidney failure or hyperparathyroidism should regularly get checkups and treatments to keep their mineral levels balanced properly.