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

## TL;DR

A rare case of fatal sepsis caused by ehrlichiosis in an elderly person without known tick exposure is reported.

## Contribution

Highlights a rare and fatal case of ehrlichiosis in an immunocompetent adult without tick exposure history.

## Key findings

- Ehrlichiosis led to fatal sepsis in an elderly patient with no known tick exposure.
- Cognitive impairment and acute encephalopathy delayed diagnosis and treatment.
- The case underscores the importance of considering ehrlichiosis in sepsis without clear tick exposure.

## Abstract

Ehrlichiosis is a vector-borne illness transmitted by the lone star tick (Amblyomma americanum). 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.