Purpura fulminans in a patient with mixed connective tissue disease

A 43-year-old lady was admitted to the intensive care unit with sepsis. She had a history of mixed connective tissue disease, Raynaud's syndrome and hypothyroidism. 2 days later, she developed a purpuric rash on her face and extremities with a livedoid background. Few days later, her distal fingers and toes became gangrenous which then had to be amputated. Laboratory investigations showed that she was coagulopathic and had multiple organ dysfunctions. Antiphospholipid antibodies were negative; however, protein C and antithrombin III levels were low. A skin biopsy showed fibrinoid necrosis in the vessel wall with microthrombi and red-cell extravasation. A diagnosis of purpura fulminans was made.