# Atypical Presentation of Infective Endocarditis: Reactive Arthritis as the First Clinical Clue

## TL;DR

A young man with atypical symptoms of infective endocarditis, including reactive arthritis and rash, was successfully treated after delayed diagnosis.

## Contribution

Highlights the diagnostic challenges of atypical IE presentations and the utility of transesophageal echocardiography and AngioVac extraction.

## Key findings

- Atypical IE presentation with reactive arthritis and vasculitis delayed diagnosis of Staphylococcus aureus bacteremia.
- Transesophageal echocardiography confirmed IE when transthoracic imaging was inconclusive.
- AngioVac-assisted extraction successfully treated left-sided vegetation and led to full recovery.

## Abstract

The clinical manifestations of infective endocarditis (IE) may be diverse and atypical, frequently mimicking rheumatologic or autoimmune disorders. The diagnosis of Staphylococcus aureus bacteremia may be delayed if early symptoms are nonspecific, despite the significant risk of underlying IE. We report a 29-year-old previously healthy male who presented with a sudden onset of fever, polyarthralgia, bilateral knee effusions, and a widespread erythematous petechial rash. Leukocytosis, thrombocytopenia, transaminitis, and significantly increased inflammatory markers were found during his initial assessment. Blood cultures revealed methicillin-sensitive Staphylococcus aureus, despite transthoracic echocardiography showing no vegetations. IE was later confirmed by transesophageal echocardiography. Following successful percutaneous AngioVac-assisted vegetation extraction (AngioDynamics, Inc., Latham, NY), the patient experienced complete recovery, and heart function returned to baseline. He completed a six-week course of intravenous cefazolin. This case emphasizes the challenges in diagnosing atypical presentations of IE, such as reactive arthritis and leukocytoclastic vasculitis. It highlights the need for early transesophageal imaging and the limits of transthoracic echocardiography. Additionally, it demonstrates the success of AngioVac extraction for a left-sided vegetation in select patients. Consideration of IE should be prompted by atypical manifestations such as rash and sterile inflammatory arthritis, especially when S. aureus bacteremia is present.