Approach to congenital infections Quiz: Ace Your Exams

A 4-day-old girl is seen in the pediatrician’s office for poor feeding and abnormal movements over the past two days. The parents report she has been irritable with poor feeding. They have witnessed several episodes of jerky movements of the arms and legs lasting about 30 seconds and then resolving spontaneously. She was born at 38 weeks gestation via vaginal delivery. The mother reports she had vesicles in the vaginal area three weeks prior to delivery but did not receive treatment. Delivery was uncomplicated. Family and surgical histories are non-contributory. Temperature is 37°C (98.6°F), pulse is 134/min, respirations are 37/min, blood pressure is 74/45 mmHg, and oxygen saturation is 98% on room air. Length is at the 25^th percentile, weight is at the 30^th percentile, and head circumference is at the 34^th percentile. Physical exam reveals an irritable infant with a vesicular rash on the arms and the head. Cardiopulmonary and abdominal exams are normal. During the exam, generalized tonic clonic seizures are witnessed that resolve without intervention after about 20-30 seconds. The patient is admitted to the hospital. Brain magnetic resonance imaging (MRI) shows edema and encephalitis. Which of the following is the best next step in management?