Bartonella Endocarditis Presenting as Leukocytoclastic Vasculitis

The case presentation discusses a 59-year-old female with acute hypoxic respiratory failure and kidney injury, accompanied by a purpuric rash, leading to a diagnosis of leukocytoclastic vasculitis associated with suspected Bartonella endocarditis. Initial examination revealed palpable purpura and a kidney biopsy indicated diffuse proliferative glomerulonephritis, raising concerns for underlying rheumatologic conditions. Subsequent work-up, including serologies, detected positivity for P ANCA and cryoglobulinemia, while blood cultures were negative. However, imaging revealed vegetation on the aortic valve, prompting the initiation of systemic antibiotics over immunosuppression. Further testing confirmed positive serology for Bartonella spp., leading to appropriate antibiotic treatment. The presentation noted that infectious endocarditis could often trigger a cutaneous vasculitis, particularly with Bartonella being an emerging pathogen in culture-negative cases. The clinical course for the patient was positive, as her conditions stabilized without the need for immunosuppression. The speaker emphasized the importance of recognizing the links between infective endocarditis, vasculitis, and potential autoimmune phenomena, while advocating for more research on these associations.