A 26-year-old Portuguese woman presented to the emergence department with a 48 hour history of progressive dispnea, generalized edema and left lower chest pain with non-productive cough. The patient had a 6 months history of inflammatory polyarthralgias involving initially interphalangeal joints, evolving, at some time later, the knees and elbows bilaterally. After ongoing rheumatologist evaluation, she started prednisolone 10 mg qd and hydroxychloroquine 400 mg qd, while waiting laboratory results. 12 days before admission, she had had symptoms of a urethritis episode, associated with unexplained anorexia and asthenia, which led her to suspend the therapeutic, even against medical advice. On examination, patient was feeling very ill, afebrile, with tachycardia (144 bpm), tachypnea (34/min), blood pressure 143/82 mmHg, peripheral oxygen saturation of 94% on 40% oxygen and raised jugular venous pressure. Intermittently she presented an obtunded state of consciousness. Aside a diffuse moderate edema and a livedoid skin discoloration, an erythematous rash over the cheeks and nasal bridge was noted. On auscultation heart sounds were found to be diminished and diffuse coarse crackles were noted on both lungs, with depressed vocal transmission in right basal thorax. Abdominal examination revealed moderate hepatomegaly and ascites. The electrocardiogram showed atrial fibrillation and low voltage QRS complexes. On chest roentgenogram (Figure 1) cardiomegaly and right pleural effusion were evident. Initial arterial blood gas showed metabolic acidosis (pH-7.134, PCO2-18 mm Hg, PO2-85 mm Hg, and HCO3-6 mEq/L). Intravenous fluid replacement was started, blood and urine were sent for culture and treatment was started with empiric antibiotics (ceftriaxone 2 g iv id plus ciprofloxacin 400 mg iv bid) and methylprednisolone 1 g iv bolus for 3 days. Patient was admitted to a high-dependency unit (HDU) for further evaluation, monitoring and support. An ultrasound of the heart showed a large circumferential pericardial effusion without signs of tamponade, which to the consulted assistant cardiologist merit only monitoring. Complementary CT scan (Figures 2 and 3) excluded pulmonary embolism or other thrombotic events, revealed an enlarged and homogeneous liver and confirmed pleuropericardial effusion and ascites. The laboratory survey revealed a white blood cell count (WBC) of 5.300 cells/mm3, with 70% polymorphonucleated cells (PMNs), a platelet count of 417.000 per mm3 and hemoglobin 7,8 g/dL. Her INR was 2.4. An extended metabolic and liver panel demonstrated: sodium 131 mmol/L, BUN 38.4 mg/dL, creatinine 1.4 mg/dL, total bilirubin 0.62 mg/dL, AST 401 U/L, ALT 85 U/L, and alkaline phosphatase 128 U/L. Ammonia was 38 μmol/L. C reactive protein 160 mg/l and ESR 87 mm/h. Urine evaluation demonstrates > 50 leucocytes and erythrocytes per high-power field, associated with proteinuria > 75 mg/dL Meanwhile, an immunologic panel, done 1 month earlier, was sent to us, showing: polyclonal hypergammaglobulinemia; positive ANA (1:160), anti-dsDNA antibodies (75 UI/mL) with positivity to anti SSA, SSB and Histone. Pleural fluid analysis showed an exsudate with no bacteria on a Gram stain. By the 2nd HDU day patient was feeling much better with remarkable edema regression. Blood gas normalized. The microbiologic results of the blood, pleural fluid and urine cultures became negative and antibiotherapy was suspended. Immunological panel revealed frank hypocomplementemia (C3 <1 UI; C4 – 9 UI; CH50 <10 UI); ANA (1:320), anti-dsDNA antibodies (175 UI/mL) with persisting positivity to anti SSA, SSB and Histone, as well as hypergammaglobulinemia and a direct positive Coombs test. A 24 hour urine collection demonstrates 2,1 g proteins. The patient was discharge by the 10th hospital day, on a therapeutic regimen of 60 mg/day of prednisolone plus hydroxychloroquine 400 mg/day, after an arrangement with the nephrologic clinic to eventually proceed to a renal biopsy.