To the editor:
We report a 65 year-old male, who received a liver transplant in 1996 and is on treatment with prednisone, mycofenolate and cyclosporin. He presented early graft rejection that was treated with pulses of methylprednisolone, and developed acute renal failure due to cyclosporin-induced nephrotoxicity requiring hemodialysis on July 2002. He has also a history of type 2 diabetes mellitus, dilated cardiomyopathy and atrial fibrillation (on anticoagulation with Acenocoumarol). He developed severe hypocalcaemia and received calcium carbonate (up to 12 g/day) and oral calcitriol (1 μg/day). The iPTH levels were maintained between 100 and 250 pg/mL and the calcium × phosphorus product was lower than 50.
In December of 2002, he presented with bilateral skin lesions on the legs, which were painful and small in diameter. Some of them had an ecchymotic appearance and others were eroded and covered by a necrotic ulcer, with violaceous borders. Peripheral pulses were present. He required opiates to control the pain and topical antibiotics. In January 2003 he was admitted to the hospital because of hemodynamic instability during hemodialysis session, fever, anemia and progression of the lesions with increasing necrosis and infection.
The laboratory parameters were: 1,900 leucocytes/mm3, hemoglobin 6.7 g/dL, calcium 7 mg/dL, phosphate 3.5 mg/dl, iPTH 72.5 pg/mL, albumin 2.6 g/dL, CRP 13.9 mg/L. The viral serology and immunological study (ANA, ANCA) were negative. Hemocultures and antigenemia were positive for Cryptococcus neoformans. Abdominal plain X-ray film: multiple vascular calcifications. Skin biopsy: Calcification within the middle layer of dermal arterioles and arteries, thrombosis within the vessels, necrosis of the adipose tissue, suggestive of calciphylaxis.
Despite the treatment with wide spectrum antibiotics and intravenous fluconazole, the progressive diminution of mycofenolate, and the surgical debridement of the lesions, the evolution was torpid and the patient died in septic shock.
CUA is a syndrome of unknown origin, characterized by areas of ischemic necrosis and calcifications of the middle layers of dermoepidermal arterioles. It is associated to chronic renal insufficiency, dialysis, and kidney transplant1. Other risk factors were identified: hyperparathyroidism, elevated calcium-phosphorus product, hyperphosphatemia,2, 4-8 adynamic bone disease,9 prolonged treatment with vitamin D supplements, calcium-based phosphorus chelating agents, oral anticoagulants, steroids, intravenous iron load, diabetes mellitus, hypoalbuminemia, deficit of proteins C or S, hyperlipidemia, local traumas and HIV infection.4,8,10-12 It is more frequent among obese and females patients.6
Diagnosis lies on clinical findings: presence of typical lesions with peripheral pulses and hyperesthesia, often resistant to analgesia.2 Histological confirmation is definitive. However it is associated to a high risk for superinfection and local dissemination of the ulcer, and some authors affirm that it should be reserved for those cases, in which the diagnosis is not clear.2,8
The approach to these patients must be multidisciplinary: treatment of underlying conditions,1, 6 control of the calciumphosphorus product and of secondary hyperparathyroidism, to limit the use of calcium-based phosphorus chelating agents and of vitamin D6,10,11, and hemodialysis with low calcium content in the dialysis fluid.6 Parathyroidectomy is indicated in cases of severe hyperparathyroidism.8 Necrotic tissue should be surgically removed and wide spectrum antibiotics should be administered. In recent studies the use of steroids,8 hyperbaric oxygen, diphosphonates, pentoxifylline or sterile larvae9 have shown promising results. In spite of an aggressive therapy the mortality is very high (60-80%), mainly due to sepsis.4
