Ehrlichiosis with pancytopenia and ARDS.

As illustrated by the case described in this report, the possibility of ehrlichiosis should be considered in the differential diagnosis of sulfasalazine toxicity/drug fever and other febrile illnesses presenting with pancytopenia/leukopenia and pulmonary abnormalities, when patients have been exposed to known tick-infested areas. Furthermore, the possibility of delayed serologic confirmation of Ehrlichia infection should be integrated into the diagnostic process as well.