Case 1: A 14-month-old infant with pericarditis.

CASE PRESENTATION A 14-month-old male infant with three weeks of fever up to 39◦C and diarrhea, presented to our emergency department. He was well until three weeks before arrival. On arrival he was alert but appeared pale and ill. Rectal temperature was 39.2◦C, heart rate was 166 beats per minute, blood pressure was 103/74 mmHg and oxygen saturation on room air was 95%. On physical examination he had normal peripheral pulses, normal heart sounds with no additional sounds or murmurs, and good air entry. He did not have enlarged lymph nodes and the throat examination revealed no abnormalities. His liver was not palpable below the costal margin, and he had mild splenomegaly. The rest of the physical examination was unremarkable. Bacterial cultures of blood and stool were obtained and were negative. Blood tests revealed white blood cell count (WBC) 15,900/mm3 with 33% neutrophils, 54% lymphocytes and 13% monocytes, hemoglobin 9 g/dL, hematocrit 29%, mean corpuscular volume 72 fL and platelets 356,000/mm3. Serum electrolytes, glucose and liver function tests were normal. C-reactive protein (CRP) was 4.1 mg/dL. Chest radiograph revealed moderate cardiac enlargement and echocardiography was done (Fig. 1). Echocardiography demonstrated normal cardiac anatomy and function, moderate to large amount of pericardial effusion, and mild thickening (6 mm) of the right lateral superior atrial wall with no interruption of the superior vena cava (SVC) to the right atrium (RA) flow. No vegetations were seen. Electrocardiogram was normal except for sinus tachycardia. On the followingmorning there was an increase in the amount of the pericardial fluid with mild tamponade effect. An echocardiography-guided pericardiocentesis was performed, and a 6 Fr. Pigtail catheter was placed percutaneously into the pericardial sac. A 100 mL of fluid was drained, which contained 3000 red blood cells/!L, 800 WBC/!L of which 74%were neutrophils and 26%were lymphocytes, glucose was 81 mg/dL and LDH 1186 IU/L. No malignant cells were detected. Bacterial cultures of pericardial fluid were negative. Serology studies done on admission suggested recent EBV infection (positive anti EBV IgM antibodies and negative anti EBV IgG and EBNA antibodies). Workup for an underlying collagen diseasewas negative. The fluid was sent for PCR for enteroviruses and EBV.