Purpura fulminans (PF) is a life-threatening disorder characterized by acute onset of progressive cutaneous hemorrhage, necrosis, and disseminated intravascular coagulation. Acute infectious PF occurs most commonly in the setting of meningococcal sepsis. When PF occurs in the setting of systemic lupus erythematosus (SLE), the catastrophic antiphospholipid antibody syndrome (CAPS) must be ruled out because urgent therapy is required. Plasmapheresis is effective in both cases, but immunosuppression (high-dose corticosteroids plus cyclophosphamide), although beneficial in patients with CAPS, could be harmful in patients with meningococcal PF. The authors report here a patient with SLE who presented to the intensive care unit with meningococcal PF, acute renal failure, and acute respiratory distress syndrome and discuss clinical similarities and laboratory differences from CAPS.