Candida glabrata Empyema Unmasked After Antibacterial Therapy: Evidence of Early Polymicrobial Pleural Infection

Fungal empyema thoracis is a rare but highly morbid pleural infection, most commonly caused by Candida species and associated with high mortality. Diagnosis is challenging, particularly in polymicrobial infections, where fungal pathogens may initially remain unrecognized. Broad-spectrum antibiotic use may facilitate fungal overgrowth and delay diagnosis. A 79-year-old man with chronic kidney disease, prior laryngectomy with permanent tracheostomy, and a history of malignancy presented with community-acquired pneumonia and parapneumonic effusion. Initial treatment with broad-spectrum antibiotics resulted in transient improvement. However, the patient subsequently deteriorated, with imaging demonstrating rapid progression to a loculated empyema with air-fluid levels. Pleural drainage yielded purulent fluid, with negative bacterial cultures. Candida glabrata was later isolated from pleural fluid. Antibacterial therapy was discontinued, and antifungal treatment with micafungin, combined with pleural drainage, led to clinical and radiological improvement. This case suggests early fungal involvement within a polymicrobial pleural infection, with subsequent fungal predominance following antibacterial therapy. The rapid progression observed contrasts with the typically indolent course of fungal empyema and highlights the importance of considering fungal etiologies in patients who fail to respond to antibiotics. Fungal empyema should be suspected in patients with persistent or worsening pleural infection despite appropriate antibacterial therapy. Early recognition and combined antifungal therapy with adequate drainage are essential to improve outcomes.