Blueberry muffin rash, hyperbilirubinemia, and hypoglycemia: a case of hemolytic disease of the fetus and newborn due to anti-Kp(a).

Hemolytic disease of the fetus and newborn occurs when maternal IgG antibodies cross the placenta and cause hemolysis of fetal red blood cells. Kp(a) is a low frequency red blood cell antigen that has rarely been implicated in hemolytic disease of the fetus and newborn. The few reported cases attributed to anti-Kp(a) have typically had minimal clinical consequences. We report a critically ill neonate who presented with purpura, respiratory failure, severe liver dysfunction, hyperbilirubinemia, hypoglycemia and anemia. This case report broadens the spectrum of neonatal disease associated with anti-Kp(a), addresses the evaluation of hemolysis with liver failure in a neonate, and emphasizes the importance of screening for antibodies to low frequency red blood cell antigens in suspected hemolytic disease of the fetus and newborn.