Calciphylaxis

Author:
Dhafer Salem, MD, MPH
Mercy Hospital and Medical Center, Chicago, Illinois

Citation:
Salem D. Calciphylaxis. Consultant. 2018;58(1):44-46.

A 33-year-old woman presented to the emergency department (ED) with lesions on her extremities. The woman had end-stage renal disease (ESRD) for which she was on hemodialysis, as well as hypertension and diastolic cardiomyopathy.

History. She had received a diagnosis of deep-vein thrombosis 10 weeks ago and had been treated with heparin and then bridged to warfarin. She had been discharged home on warfarin with only a 7-day supply of the medication and was supposed to follow up with her anticoagulation clinic to get the prescription refilled, but she had been unable to do so.

At presentation, she reported that the skin lesions had begun to develop before she had taken her first dose of warfarin during her previous admission 10 weeks ago. She had visited her primary care physician multiple times since then. At first she had been told that the lesions were hematomas and that they would resolve on their own, then she had been told that the lesions were eschar and was referred to a dermatologist. However, her pain and pruritus had worsened, prompting her ED visit.

NEXT: Physical examination

Physical examination. At presentation, the patient had black, dry, scaly, shiny, warm, tender, and extremely pruritic lesions with excoriations on her extremities, including the dorsal right hand, the left medial forearm, and the thighs and legs bilaterally (Figures 1-4). The lesions were at different stages of healing. No bruises, blanching or nonblanching petechial lesions, or hematomas were present. A nodule was palpated on the right medial thigh. Scars were present on the bilateral knees from previous surgical treatment of ligament calcification (Figure 5).

Figure 1: Lesions on the left medial forearm.

Figure 2: Black, dry, tender, extremely pruritic lesions on the patient’s left dorsal hand.

Figure 3: Lesions on the right anterior thigh.

Figure 4: Lesions on the left medial thigh.

Figure 5: Scars on the bilateral knees from surgical treatment of ligament calcification.

Given her history of warfarin therapy, suspicion for warfarin-induced skin necrosis was in the differential diagnosis; however, she had taken warfarin only for 7 days and had last taken the anticoagulant more than 2 months before presentation.

NEXT: Diagnostic tests

Diagnostic tests. Laboratory test results included an elevated erythrocyte sedimentation rate above 130 mm/h, an elevated C-reactive protein level of 198.8 mg/L, and an elevated parathyroid hormone level of 1200 pg/mL. Coagulation test results were normal, including international normalized ratio, prothrombin time, partial thromboplastin time, fibrinogen level, thrombin time, antithrombin level, protein C level, protein S level, and vitamin K-dependent clotting factors 2, 7, 9, and 10.

Radiographs showed diffuse vascular and subcutaneous calcification (Figures 6-9). A biopsy of the right thigh lesion showed calcification of the small vessels and several fibrin thrombi.

Figure 6: Radiographs of the hands showed arterial calcification (arrows).

Figure 7: Radiographs of the feet showed calcification of the right Achilles tendon (left arrow) and arterial calcification in the left foot (right arrow).

Figure 8: Radiograph of the right foot showed arterial calcification (arrow).

Figure 9: Radiograph of the right thigh showed calcification of the femoral artery (upper arrow) and calcification of the patellar ligament (lower arrow).

NEXT: Discussion

Discussion. She received a diagnosis of calciphylaxis, a condition characterized by skin ischemia resulting from calcification of dermal arterioles. The ischemia leads to painful necrotic lesions on the legs, buttocks, abdomen and other areas of adiposity, or in areas with lower blood supply such as the fingertips. Although it is rare, calciphylaxis occurs more often in persons with ESRD.

Treatment usually is with long-term intravenous sodium thiosulfate, along with wound care and pain management. The prognosis is generally poor, given the generally low effectiveness of treatment and the increased rate of associated infection.