Index Of Suspicion In The Nursery

A 2.9-kg female infant is born at 35 weeks' gestation to a 33-year-old G4P3 woman via cesarean section due to chronic hypertension complicated by superimposed preeclampsia. The mother's blood type is A-negative; the antibody screen is positive for anti-D, anti-C, and anti-G antibodies; she has no prior history of sensitization; and her serologies are negative. The Apgar scores are 7 and 9 at 1 and 5 minutes, respectively. At birth, the infant appears pale and exhibits tachycardia, moderate hepatosplenomegaly, tachypnea, and mild respiratory distress requiring supplemental oxygen. Complete blood count and blood cultures are obtained, and ampicillin and gentamicin are started. The admission hematocrit is 21% (0.21), with a reticulocyte count of 64%. An umbilical venous catheter is placed for intravenous (IV) access. The infant receives a transfusion of packed red blood cells for significant anemia associated with tachycardia. Prophylactic phototherapy is started because of Rh sensitization. The cord blood bilirubin measures 11.4 mg/dL (195 mcmol/L). The infant's blood type is A-negative, and the antibody screen is positive for anti-D and anti-C antibodies, with a positive direct Coombs test. The red blood cell phenotype reveals the presence of “C” antigen. This is a very uncommon antigen in an Rh-negative infant, but the antigen had stimulated the anti-C antibodies that traversed the placenta and caused severe hemolysis of the newborn. At 7 hours of age, the infant's bilirubin is 16 mg/dL (273.6 mcmol/L). She is given two doses of intravenous immune globulin, and phototherapy is intensified. After 24 hours of intensive phototherapy, the infant develops a large reddish-purple discoloration on her abdomen that resembles a severe burn (Fig. 1). The well-demarcated, erythematous, purpuric rash is present over the areas closely exposed to the phototherapy lights and does not blanch with diascopy. No vesiculobullous eruptions, edema, or tenderness is noted. The unexposed …