Fulminant Tuberculous Pericarditis Presenting as Cardiac Tamponade in an Infliximab-Treated Patient.

Tuberculous pericarditis (TBP) is a rare but potentially life-threatening manifestation of extrapulmonary tuberculosis (TB), representing a clinically important subset of pericarditis cases. Diagnostic uncertainty arises from variable symptoms and the low sensitivity of available tests. Although culture is the gold standard, it is reliable but too slow to enable a timely diagnosis. Acute and fulminant presentations have been reported in immunosuppressed patients. A 61-year-old woman, recently receiving infliximab and corticosteroids for Crohn's disease, presented to the emergency department with signs of sepsis and obstructive shock. Echocardiography revealed a large pericardial effusion, prompting urgent pericardiocentesis. Analysis of pericardial fluid was negative for acid-fast bacilli. She remained unwell, with persistently elevated inflammatory markers, bilateral pleural effusions, pulmonary nodules, intra- and extra-thoracic lymphadenopathy, and subsequently developed heart failure. After nearly two weeks, endobronchial ultrasound-guided lymph node aspiration with Cepheid GeneXpert TB PCR confirmed rifampicin-sensitive Mycobacterium tuberculosis. This case is unusual because it combines three rare features: fulminant TBP presenting as acute tamponade, reactivation of TB in the setting of anti-tumor necrosis factor therapy, and transient left ventricular systolic dysfunction following pericardial drainage. It highlights the importance of considering TB pericarditis in immunosuppressed patients, recognizing the limitations of conventional fluid-based diagnostics, and pursuing timely tissue sampling to confirm the diagnosis and guide appropriate therapy.