Review ArticlesEmpyema Necessitans Due to Methicillin-Sensitive Staphylococcus aureus Case Report and ReviewDeSuza, Kayla DO∗; Bush, Larry M. MD, FACP†,‡Author Information From the ∗Wellington Regional Medical Center, Wellington †Charles E. Schmidt College of Medicine, Florida Atlantic University ‡University of Miami–Miller School of Medicine, Palm Beach County, Florida, Regional Campus, Boca Raton, FL. Correspondence to: Larry M. Bush, MD, Comprehensive Infectious Diseases, Wellington Regional Medical Center, 10115 Forest Hill Blvd, Suite 102, Wellington, FL 33414. E-mail: [email protected]. Conflicts of interest and sources of funding: none declared. Infectious Diseases in Clinical Practice: May 2020 - Volume 28 - Issue 3 - p 130-133 doi: 10.1097/IPC.0000000000000839 Buy Metrics AbstractIn Brief Empyema refers to a collection of pus in the pleural cavity. Empyema necessitans is a rare complication of an empyema that refers to an insidious extension of the pus through the parietal pleura into the neighboring subcutaneous tissue of the chest wall or, less often, other thoracic structures. Left untreated, the purulent material may penetrate the chest wall forming a fistula or subcutaneous abscess. Drainage and empiric antimicrobial therapy should be started when the diagnosis is made and adjusted once the infecting organism is identified. Mycobacterium tuberculosis and Actinomyces species, both generally slow-growing microbes, remain the most common pathogens associated with the development of empyema necessitans. Although rarely encountered in the postantibiotic era, acute infections involving pyogenic organisms including Staphylococcus aureus may serve as the etiologic agents associated with this problematic subset of pleural effusion. The majority of reported cases of empyema necessitans due to S. aureus have occurred with strains that are methicillin resistant. This case describes a 70-year-old man who, after a month long of symptoms, presented with empyema necessitans due to methicillin-sensitive S. aureus. This case underscores the importance of diagnosing an empyema and treating early with antibiotics in order to avoid subsequent surgical intervention if and when empyema necessitans should develop. Parapneumonic effusions commonly occur in cases of bacterial pneumonia and are termed empyemas if infected. Left unrecognized or untreated, the infl ammatory purulent process may penetrate the chest wall and into other adjacent structures, most often the anterior chest wall, a condition known as empyema necessitans. Historically, Mycobacterium tuberculosis and Actinomyces have accounted for the majority of such occurrences. In the post-antibiotic era, pyogenic organisms, including Staphylococcus aureus are infrequent etiologic agents. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.