Subcutaneous calcification presenting in a patient with mixed connective tissue disease and cutaneous polyarteritis nodosa.

Subcutaneous calcification often occurs in connective tissue diseases, most commonly scleroderma and dermatomyositis, but is rarely found in mixed connective tissue disease (MCTD). Cutaneous polyarteritis nodosa (PAN) is usually a primary skin disorder and although associated with connective tissue disease, has not been reported previously in MCTD. Calcinosis in cutaneous PAN is not a recognized feature. We describe the case of a 37-year-old woman who presented with tender ulcerated subcutaneous nodules on the lower legs consistent with cutaneous PAN, and she also showed features of MCTD with extensive secondary subcutaneous calcification. The use of systemic immunosuppressive treatment has improved the clinical features of PAN and MCTD but treatment of the calcification has proved challenging. No single medical or surgical treatment has been shown to be consistently effective in subcutaneous calcification, but the introduction of diltiazem in our patient has resulted in some improvement.