Fever, Fussiness, and Poor Feeding in a 2-month-old Boy

1. Alyssa A. Kerber, MD*,†,‡ 2. Meredith S. Campbell, MD* 3. Sarah C. Rhodes, MD* 4. Elizabeth H. Ristagno, MD, MS† 1. *Department of Pediatric and Adolescent Medicine and 2. †Division of Pediatric Infectious Disease, Mayo Clinic, Rochester, MN 1. Address correspondence to Elizabeth H. Ristagno, MD, MS, Department of Pediatric and Adolescent Medicine, Mayo Clinic, 200 First St SW, Rochester, MN 55905. E-mail: ristagno.elizabeth{at}mayo.edu A previously healthy infant is brought to a pediatrician at 48 days of age with fussiness, poor feeding, and a fever (100.4°F; 38.0°C). He has a normal white blood cell count and urine, and blood cultures are negative. A diagnosis of left otitis media is made and he completes a 10-day course of cefdinir. Three days after completion of the antibiotic course, he is brought to the emergency department at an outside facility with worsening fussiness, poor feeding, and a reported fever (100.4°F; 38.0°C) at home, measured the previous night. He appears ill with substantial tachycardia but without specific findings on examination. He is afebrile on initial arrival. The white blood cell count is increased to 18.3 × 109/L with a neutrophilic predominance. There is concern for urinary tract infection, with bacteria and clusters of white blood cells on microscopy, although not enough urine is collected to culture. A blood culture is obtained. He receives a 20-mL/kg fluid bolus and a dose of ceftriaxone. His tachycardia improves and he is then transferred to our hospital for further care. Upon his arrival, he is noted to be febrile …