ABSTRACT
INTRODUCTION: Infective endocarditis (IE) has been known as the great imitator due to variable clinical manifestation, making its diagnosis challenging. A missed diagnosis could lead to inappropriate therapy. We presented a rare case of blood culture-negative infective endocarditis (BCNIE) due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli manifest with cutaneous vasculitis and generalized lymphadenopathy. We highlighted its diagnostic challenge and management. CASE ILLUSTRATION AND DISCUSSION: A 36-year-old male with known asymptomatic ruptured sinus of Valsalva (SOV) presented with fever of unknown origin for six months, fatigue, weight loss with a history of multiple hospitalizations. The physical examination revealed a continuous murmur at Erb's point, cutaneous vasculitis, and bilateral inguinal lymphadenopathy. The laboratory result was leukocytosis and elevated C-Reactive Protein (CRP). Generalized lymphadenopathy was detected from the thorax and abdominal Computed Tomography (CT) Scans. Positive Anti Nuclear Antibody (ANA) Indirect Immunofluorescence (IF) speckled pattern led us to consider an autoimmune as the etiology, but we still considered IE as a differential diagnosis due to history of structural heart disease. Detection of multiple tiny oscillating masses at the tricuspid valve from the echocardiogram and cardiac CT led to possible IE diagnosis. Negative three consecutive blood cultures led the diagnosis to BCNIE. Surgery was performed to evacuate the vegetations, repair the SOV, and tricuspid valve replacement with a bioprosthetic valve. These results in improvement of the patient's condition. ESBL-producing Escherichia coli yielded in tissue culture made the diagnosis of IE became definite. CONCLUSION: ESBL-producing Escherichia coli should be considered as the etiology of BCNIE. Cutaneous vasculitis and generalized lymphadenopathy as a manifestation of IE could lead to diagnostic confusion. A thorough investigation will help clinician to avoid delay or inappropriate treatment that could be detrimental for the patient.
