Infantile pyknocytosis: A rare cause of newborn hemolytic anemia two case reports

Abstract

Infantile pyknocytosis (IP) is a rare cause of neonatal hemolytic disease. The exact etiology of this entity remains unclear. It is characterized by prolonged jaundice and transient hemolytic anemia, combined with increased proportion of pyknocytes in peripheral blood smear. Diagnosis is exclusively based on the detection of a higher proportion of pyknocytes in peripheral blood smear. IP is a self-restricted disease. In this case series study we present the diagnostic approach, therapeutic intervention and outcome of two neonates, presented with unconjugated hyperbilirubinemia and major hemolysis, the 17th and 21st day of life respectively, treated with phototherapy and excellent outcome. Despite the low incidence of this entity, IP should be included in the differential diagnosis in case of prolonged neonatal jaundice not well explained by other common of hemolytic anemia.