Calciphylaxis
| Calciphylaxis | |
|---|---|
 |
|
| Calciphylaxis on the abdomen of a patient with end stage kidney disease. Markings are in cm. | |
| Classification and external resources | |
| ICD-9-CM | 275.49 |
| DiseasesDB | 1897 |
| eMedicine | derm/555 |
| MeSH | D002115 |
Calciphylaxis, or calcific uremic arteriolopathy (CUA), is a syndrome of calcification of the blood vessels, blood clots, and skin necrosis. It is seen mostly in patients with stage 5 chronic kidney disease, but can occur in the absence of kidney failure. It results in chronic non-healing wounds and is usually fatal. Calciphylaxis is a rare but serious disease, believed to affect 1-4% of all dialysis patients.
Calciphylaxis is one type of extraskeletal calcification. Similar extraskeletal calcifications are observed in some patients with hypercalcemic states, including patients with milk-alkali syndrome, sarcoidosis, primary hyperparathyroidism, and hypervitaminosis D.
The first skin changes in calciphylaxis lesions are mottling of the skin and induration in a livedo reticularis pattern. As tissue thrombosis and infarction occurs, a black, leathery eschar in an ulcer with adherent black slough are found. Surrounding the ulcers is usually a plate-like area of indurated skin. These lesions are always extremely painful and most often occur on the lower extremities, abdomen, buttocks, and penis. Because the tissue has infarcted, wound healing seldom occurs, and ulcers are more likely to become secondarily infected. Many cases of calciphylaxis end with systemic bacterial infection and death.
Calciphylaxis is characterized by the following histologic findings:
Severe forms of calciphylaxis may cause diastolic heart failure from cardiac calcification, called heart of stone.
The cause of calciphylaxis is unknown. It does not seem to be an immune type reaction. In other words, calciphylaxis is not a hypersensitivity reaction (i.e., allergic reaction) leading to sudden local calcification. Clearly, additional factors are involved in calciphylaxis. It is also known as calcific uremic arteriolopathy; however, the disease is not limited to patients with kidney failure. The current belief is that in end-stage kidney disease, abnormal calcium and phosphate homeostasis result in the deposition of calcium in the vessels, also known as metastatic calcification. Once the calcium has been deposited, a thrombotic event occurs within the lumen of these vessels, resulting in tissue infarction. It is unknown what the triggers are that cause the thrombotic and ischemic event. Reported risk factors include female sex, obesity, elevated calcium*phosphate product, medications such as warfarin, calcium-based binders, or systemic steroids, protein C or S deficiency, low blood albumin levels, and diabetes mellitus.
...
Wikipedia