Delayed dengue-associated hemorrhagic fibrinous pericarditis with cardiac tamponade: clinicopathologic characterization of a rare post-infectious cardiovascular complication

Abstract Dengue-associated cardiac tamponade remains a rare cardiovascular complication, particularly in elderly patients with underlying thrombocytopenic or autoimmune vulnerability. We report the case of an 88-year-old Tanzanian female with chronic immune thrombocytopenia and persistent antiphospholipid antibody positivity who presented to a tertiary care center in the United Arab Emirates with progressive dyspnea, chest discomfort, and impending hemodynamic collapse approximately three weeks after conservatively managed dengue infection. Echocardiography demonstrated circumferential pericardial effusion with fibrinous strands and tamponade physiology. Emergent pericardiocentesis yielded frank hemorrhagic fluid and resulted in dramatic symptomatic and functional recovery. The patient continued to improve throughout hospitalization and was discharged ambulatory without recurrent hemodynamic compromise. Serial pericardial fluid analyses demonstrated evolution from an acute hemorrhagic inflammatory phase toward an organizing fibrinous exudative stage. Extensive investigations for tuberculous, malignant, bacterial, and connective tissue disease etiologies were unrevealing. Cytology demonstrated inflammatory hemorrhagic smears with hemosiderophages and no malignant cells, while pericardial fluid dengue immunoglobulin positivity strengthened the temporal and immunologic association with recent dengue infection. This case highlights delayed dengue-associated hemorrhagic fibrinous pericarditis as a rare but potentially life-threatening inflammatory cardiovascular complication. It emphasizes the importance of recognizing dengue-associated pericardial disease following recent infection and underscores the need for systematic exclusion of tuberculosis and malignancy in elderly patients presenting with hemorrhagic pericardial effusion.