Ehrlichiosis infection in a 5-year-old boy with neutropenia, anemia, thrombocytopenia, and hepatosplenomegaly

Ehrlichiosis should be considered in the differential diagnosis of any pati ent with recent fever, pancytopenia, hepatosplenomegaly, and history of tic k exposure. We present a previously healthy 5-year-old boy who was referred to the Hematology-Oncology Clinic to consider a bone marrow etiologic proc ess after his pediatrician discovered progressive neutropenia, anemia, thro mbocytopenia, and hepatosplenomegaly accompanied by 2 days of fever. Bone m arrow aspirate and biopsy were nonrevealing. Because of the history of a re cent tick bite, a diagnosis of ehrlichiosis infection was considered and ul timately confirmed by IgG-specific serum testing. The patient's fever was t reated symptomatically with acetaminophen, and symptoms resolved on their o wn without intervention. Ehrlichiosis is a tick-borne infection that occurs throughout the spring and summer, often causing findings that mimic a mali gnancy or serious hematologic disorder. The diagnosis should be considered in any person living in tick-infested areas and can be confirmed by polymer ase chain reaction or serum antibody titers. Treatment with doxycycline can lead to rapid clinical improvement if the diagnosis is made early.