Pulmonary Embolism as a Rare Complication of Anaplasmosis: A Case Report.

Pulmonary embolism is an exceptionally rare complication of anaplasmosis. We report a case of a 69-year-old man with acute Anaplasma phagocytophilum infection who developed bilateral pulmonary emboli and pneumonia despite appropriate doxycycline therapy. Evaluation revealed positive antiphospholipid antibodies, raising concern for antiphospholipid syndrome; however, interpretation was confounded by acute infection and ongoing anticoagulation, limiting the ability to distinguish transient infection-associated antibody positivity from an underlying thrombophilic disorder. This case highlights the need to consider venous thromboembolism in patients with anaplasmosis presenting with chest pain or respiratory symptoms and underscores the diagnostic uncertainty surrounding antiphospholipid antibody testing in the setting of acute infection and thrombosis.