Case 1: Term Newborn with Purple Rash at Birth

A male infant is born at 37 weeks and 6 days of gestation via planned cesarean delivery because of predicted macrosomia. The mother is a 23-year-old primigravida whose pregnancy had been complicated only by abnormal surveillance fetal ultrasonography findings concerning for fetal cardiac defect. Fetal echocardiography performed at approximately 32 weeks’ gestation revealed biventricular hypertrophy and a dysplastic tricuspid valve with mild-to-moderate insufficiency. The pregnancy had been otherwise unremarkable. The mother denies use of drugs, illicit or prescription, alcohol, and tobacco during the pregnancy. Prenatal testing had shown the following results: human immunodeficiency virus, nonreactive; hepatitis B surface antigen, negative; rapid plasma reagin, nonreactive; and rubella, immune. Birthweight and length are 4.33 kg (97th percentile) and 51 cm (69th percentile), respectively. He is admitted to the NICU with a “blueberry-muffin” rash. Examination on admission is significant for macroglossia, right preauricular pit, multiple erythematous and purple nodules, purpura, petechiae, ankyloglossia, and...