# An Atypical Presentation of Rocky Mountain Spotted Fever Presenting as Progressive Vision Loss: A Case Report

## TL;DR

A man with HIV presented with worsening vision loss and was later diagnosed with Rocky Mountain Spotted Fever, highlighting the disease's atypical presentation in immunocompromised individuals.

## Contribution

This case report highlights the atypical presentation of RMSF as progressive vision loss in an immunocompromised patient.

## Key findings

- The patient's symptoms did not include the classic triad of fever, rash, and headache typically associated with RMSF.
- Serological testing confirmed RMSF despite the absence of known tick exposure or typical symptoms.
- The case underscores the importance of considering RMSF in immunocompromised patients with unexplained neurological or visual symptoms.

## Abstract

This case report describes a 49-year-old immunocompromised male with human immunodeficiency virus (HIV) who presented with progressive bilateral vision loss. He initially noticed blurriness and visual distortion in the right eye several months prior, which gradually progressed to involve the left eye with worsening peripheral vision and intermittent diplopia. Despite several evaluations and empiric treatment, his symptoms continued to worsen. Prior imaging and lumbar puncture (LP) were inconclusive. After extensive evaluation by ophthalmology, neurology, and infectious disease, the differential diagnosis was expanded to include infrequent causes, including infectious processes. A panel of diagnostic tests ultimately revealed Rocky Mountain Spotted Fever (RMSF). While it is typically a curable disease, RMSF can be a potentially lethal disease caused by the bacteria Rickettsia rickettsii. Human-to-human transmission is not known to occur. The patient denied tick bites or exposure risk; however, an unknown tick exposure could have occurred. At the time of diagnosis, the patient was significantly immunocompromised. Given this immunocompromised state, it is possible that the patient was more susceptible to infection transmission. Despite the absence of the classic triad of fever, rash, and headache, serological testing ultimately led to the diagnosis of RMSF, demonstrating the need for a broad differential and a high index of suspicion for this potentially life-threatening illness, especially in an immunocompromised patient.