Purulent Streptococcus intermedius Pericarditis in the Setting of Histoplasma Mediastinal Lymphadenitis: A Case...

Purulent pericarditis is a rare and potentially life-threatening condition characterized by infection of the pericardial space. We describe a case of purulent bacterial pericarditis in a 41-year-old male with no significant medical or surgical history who had concomitant pulmonary Histoplasma infection. Streptococcus intermedius was the bacteria directly responsible for the pericardial infection, though co-infection with histoplasmosis likely predisposed him to develop purulent pericarditis. We hypothesize histoplasmosis caused mediastinal lymphadenopathy, facilitating contact between a necrotic lymph node and the pericardium and contiguous suppuration of bacteria to the pericardial space. We treated S. intermedius and Histoplasma capsulatum with ceftriaxone and amphotericin B, respectively. Additionally, the patient presented in cardiac tamponade requiring emergent pericardiocentesis and drain placement. His course was also complicated by pericardial constriction. Cardiac magnetic resonance confirmed this, showing inflamed pericardium and abnormal septal motion with inspiration, and he had symptoms refractory to antimicrobials and anti-inflammatories. As such, he required pericardiectomy. This case demonstrates maintaining suspicion for secondary infectious foci as a contributor to the pathogenesis of purulent pericarditis is important, as pulmonary histoplasmosis played a pivotal role in allowing S. intermedius to spread to the pericardium but was not the primary infection. It also highlights the multifaceted evaluation and management of purulent pericarditis, highlighting the role of echocardiography and emergent pericardial drainage if cardiac tamponade is present, the importance of targeted antimicrobial therapy, the superior ability of cardiac magnetic resonance to identify pericardial constriction as a sequela of purulent pericarditis, and indications for pericardiectomy.