A case of functional asplenia and pneumococcal sepsis.

Asplenia may refer to the spleen's surgical removal, functional impairment, or congenital absence. It is a risk factor for the development of severe bacterial infection. Functional asplenia is likely the most common presentation of this entity and has many etiologies. Those that are previously undiagnosed may present completely well until an episode of overt sepsis develops. The true incidence of mortality secondary to functional asplenia remains elusive. As lifetime mortality remains exceedingly high in the asplenic population regardless of etiology, markers of hyposplenism are important to detect. The present report describes an infant with trisomy 21 and previously undiagnosed functional asplenia who ultimately experienced overwhelming pneumococcal sepsis with features of Waterhouse-Friderichsen syndrome and died within 12 hours of initial presentation. It is a poignant reminder of what features to be cognizant of on peripheral blood smear in a previously well child, who may be at risk for a devastating consequence.