Ehrlichiosis: A Unique Presentation of Fatal Sepsis in an Immunocompetent Adult.

Ehrlichiosis is a vector-borne illness transmitted by the lone star tick (). Most patients have risk factors for tick exposure, such as hobbies or careers involving hunting, camping, and hiking. This case exposes a rare case of severe ehrlichiosis, ultimately resulting in fatal sepsis, in an elderly patient without any reported tick bites or exposures. This patient had a history of cognitive impairment, which was confounded by acute encephalopathy at presentation. Unfortunately, this hindered his ability to report any known tick exposures, which posed a challenge in the diagnosis and ultimately delayed treatment as there were no clear findings of a tick bite or known exposures.