Table 2 Differential diagnosis of Calciphylaxis.

Peripheral Vascular Disease

Lower extremities

Absent pulses, abnormal ankle brachial pressure index

Venous ulcer

Above the malleoli

Reddish brown discoloration with brawny edema suggesting venous stasis

Leucocytoclastic vasculitis

Symmetric, lower extremities

Palpable purpura evolve into hemorrhagic papules with milder symptoms; Positive serology/cryoglobulins; Characteristic skin biopsy

Pyoderma gangrenosum

Lower extremities

Associated with IBD and malignancy; Starts as a pustule, enlarges into violaceous erythematous plaque which ulcerates with heaped-up borders

Disseminated Intravascular Coagulation

Generalized

Widespread rapidly developing purpura. Associated with shock or disseminated infection and multi organ failure; A consumption coagulopathy

Warfarin-induced skin necrosis

Extremities, breast, trunk

History of warfarin use; May have associated protein C and S deficiency; Starts as erythematous macules which become edematous and necrotic; Skin biopsy shows fibrin thrombi within the blood vessels with interstitial hemorrhage

Atheroembolic phenomena

Diffuse

Starts as purpura after vascular procedure such as angiography

Nephrogenic systemic fibrosis

Symmetrical, extremities

Commonly associated with end stage renal disease on dialysis; May be associated with Gadolinium contrast agent; Presents as papules or plaques – areas of thick hardened skin with hyperpigmentation; Biopsy shows increased collagen bundles and fibroblast like cells

Hypercoagulable states e.g. Protein C & S deficiency

Trunk and extremities

History of thromboembolic events; Skin necrosis develops after initiating warfarin; Ecchymotic skin lesions coalesce and ulcerate leading to necrosis