Bartonella henselae infection associated with a multisystemic thrombo-inflammatory syndrome in an immunocompetent adult

Background: Bartonella henselae infection is traditionally associated with self-limited cat-scratch disease but may occasionally present with severe systemic manifestations. Case presentation: We report a 43 year-old immunocompetent man who developed a multisystem thrombo-inflammatory syndrome with thrombocytopenia, renal involvement, thrombotic events, ocular ischemia, and transient lupus anticoagulant positivity, initially suggestive of catastrophic antiphospholipid syndrome. Extensive investigations were unrevealing until whole blood PCR detected B. henselae. Retrospective histopathology revealed small-vessel endothelial injury compatible with microangiopathy. Doxycycline therapy was followed by clinical improvement, normalization of platelet counts, and resolution of thrombotic manifestations Conclusion: This case highlights the diagnostic complexity of systemic Bartonella infection and the need to consider infectious triggers in unexplained thrombo-inflammatory presentations, even in immunocompetent individuals.