Migratory purpura in a patient with mediastinitis due to methicillin-resistant Staphylococcus aureus

Mediastinitis is a devastating complication associated with substantial mortality, morbidity, hospital stay, and costs. Isolation of methicillin-resistant Staphylococcus aureus (MRSA) is reported to cause an even higher mortality and morbidity. We present herein a patient with mediastinitis presenting with cutaneous vasculitis as part of initial symptomatology. A 70-year-old man presented with an ascending aortic aneurysm and underwent an aortic root replacement procedure with a prosthetic valved conduit; he was discharged on day 7 after an uneventful postoperative course. A week after his discharge, he was re-admitted to hospital with sternal dehiscence, elevated white cell count (15 10/l), highgrade fever, and purpuric skin lesions appearing first on the proximal lower extremities and armpits (Figure 1). He was given vancomycin and gentamicin following a presumptive diagnosis of mediastinitis and sepsis. A repeat sternotomy for valved conduit replacement was performed with mediastinal exploration and irrigation. In addition to serial blood cultures, tissue cultures were taken during exploration, all of which revealed MRSA infection. Vancomycin was continued upon microbiologic identification until serial blood and drainage cultures proved negative. Over the next week, the skin rash redistributed to the distal lower extremities around the ankles and the genitalia, and spread thoroughly over the upper extremities. Cutaneous biopsy of the skin lesions revealed a leukocytoclastic angiitis andwas negative for immunedeposits upon immunofluorescence study. Serum IgE levels were not elevated and no eosinophilia was observed. His postoperative course after the sternal revision was uneventful. His skin rash disappearedonday10whenhewas on systemicantibiotics and topical corticosteroid, and he was discharged on day 24. In most cases of mediastinitis, coagulase-negative staphylococci and MRSA have been isolated as the etiological agent. The cornerstone of treatment of mediastinitis is prompt re-operation with irrigation and complete excision of the infected/necrotic tissue. Staphylococcal infection with a vasculitis component is rare, but a known phenomenon. However, selected cases