SHM Converge Scientific Abstract ePoster Gallery-Infective Endocarditis Mimicking Anca-Associated Vasculitis: A Diagnostic Challenge

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This case report describes a 65-year-old man with fatigue, hemoptysis, weight loss, purpuric rash with hemorrhagic bullae, acute renal failure, proteinuria, hematuria, and elevated inflammatory markers. Because his presentation included systemic, renal, and skin findings, he was initially suspected to have ANCA-associated vasculitis. Laboratory testing supported this concern with positive cANCA and proteinase-3 antibodies, and skin biopsy showed leukocytoclastic vasculitis.<br /><br />However, a new systolic murmur prompted cardiac evaluation. Transthoracic and transesophageal echocardiography revealed aortic valve vegetation and a large mitral valve mass. Despite negative blood cultures, the possibility of infective endocarditis remained high. The patient was transferred to a tertiary center and underwent aortic and mitral valve replacement. Valve tissue cultures ultimately grew Streptococcus gallolyticus, confirming culture-negative infective endocarditis rather than primary vasculitis.<br /><br />He completed a 6-week course of intravenous antibiotics and was referred for colonoscopy because of the association between Streptococcus gallolyticus and colorectal malignancy.<br /><br />The report emphasizes that infective endocarditis and ANCA-associated vasculitis can have overlapping clinical, laboratory, and histologic features, including rash, renal involvement, and positive ANCA results. ANCA positivity occurs in an estimated 18% to 43% of infective endocarditis cases, which can cause diagnostic confusion and delay appropriate therapy. The authors stress the importance of considering endocarditis in culture-negative patients with vasculitic features and of using echocardiography, tissue cultures, and multidisciplinary collaboration to establish the correct diagnosis and guide management.

Asset Subtitle

Massah T. Bassie

Meta Tag

Author List Massah T. Bassie, Rahul Gaiba, Shakeera Dunn, Simran Patel

Category Clinical Vignettes

Concept Infective Endocarditis

Concept ANCA-Associated Vasculitis

Concept ANCA positivity

Concept Echocardiographic Vegetation

Concept New Murmur

Distinguished Non-Finalist

Presenter Organization Bayhealth Medical Center

Presenting Author Massah T. Bassie

Track Adult

Keywords

infective endocarditis

ANCA-associated vasculitis

culture-negative endocarditis

Streptococcus gallolyticus

cANCA positivity

proteinase-3 antibodies

leukocytoclastic vasculitis

aortic valve vegetation

mitral valve mass

acute renal failure

Infective Endocarditis

ANCA-Associated Vasculitis

ANCA positivity

Echocardiographic Vegetation

New Murmur