Rothia mucilaginosa Prosthetic Valve Endocarditis Presenting as a Thrombotic Microangiopathy Mimic With Catastrophic...

Rothia mucilaginosa is an uncommon but increasingly recognized opportunistic pathogen capable of causing invasive infection, particularly in patients with prosthetic material and immunocompromised states. Rarely, severe systemic infections may present with thrombotic microangiopathy-like syndromes mimicking thrombotic thrombocytopenic purpura (TTP), creating significant diagnostic uncertainty. We present a case of fulminant Rothia mucilaginosa prosthetic valve infective endocarditis initially presenting as a TTP/disseminated intravascular coagulation (DIC) mimic in a 60-year-old man with severe thrombocytopenia, schistocytosis, hemolytic anemia, encephalopathy, and intracranial hemorrhage. Due to concern for evolving TTP, emergent plasmapheresis and corticosteroids were initiated prior to identification of the underlying infectious process. Blood cultures subsequently grew Rothia mucilaginosa, and transesophageal echocardiography demonstrated prosthetic valve endocarditis. The patient's course was complicated by progressive bilateral intracranial hemorrhage, septic emboli, and catastrophic neurologic deterioration despite aggressive multidisciplinary management. This case highlights the diagnostic challenge of distinguishing primary TTP from infection-associated thrombotic microangiopathy and emphasizes the importance of maintaining a broad differential diagnosis in patients presenting with thrombocytopenia, schistocytosis, neurologic dysfunction, and sepsis physiology, particularly in the setting of prosthetic cardiac valves.