BackgroundAbrupt and life-threatening presentations in connective tissue diseases (CTD) are rarely reported. Their early recognition and specific management could change course disease. SLE is a multisystem inflammatory disease that is often difficult to diagnose in the emergency department (ED).Case presentationA 26-year-old woman presented to the ED with a 48 hour history of progressive dispnea, generalized edema and left lower chest pain with non-productive cough. On examination, patient was feeling very ill, afebrile, tachycardic, tachypneic and a peripheral oxygen saturation of 94% on 40% supplemented oxygen with raised jugular venous pressure was noted. Intermittently, she presented an obtunded state of consciousness. A large pericardial, pleural and abdominal effusion was confirmed and a broad differential diagnosis was made. The patient had a 6 months history of inflammatory polyarthralgias involving initially interphalangeal joints, evolving, sometime later, the knees and elbows bilaterally and she was started glucocorticoids. 12 days before admission, she had had symptoms of a urethritis episode. In the context of an immunosupressed patient, with initial focal urologic complains, evidence of multiorgan dysfunction and a picture resembling a distributive shock, dictated a low threshold for sepsis.ConclusionsSeparating an acute episode of SLE from sepsis, on emergency grounds, can even be the most challenging decision. In the ED, acute life-threatening and multisystemic conditions should arise the suspicion of autoimmune diseases, particularly SLE.