2025 guideline updates for community-acquired pneumonia diagnosis and management

Community-acquired pneumonia (CAP) is a common condition evaluated and managed in the emergency department (ED) setting. Guidelines published in 2007 and 2019 from the American Thoracic Society (ATS) and Infectious Diseases Society of America provide recommendations for CAP, but there are a variety of studies that have been published since the release of these guidelines. The ATS published updated guidelines in 2025, which discuss imaging, antibiotic therapy, and corticosteroids. The updated guidelines support the use of lung ultrasound for diagnosis of CAP when used by experienced clinicians. For patients with CAP and positive viral testing who are otherwise healthy, the 2025 guidelines suggest not prescribing antibiotics based on very low-quality evidence, though there are several factors that should be considered (e.g., imaging findings). Antibiotics should be administered in those with comorbidities or admitted patients, as well as those with imaging findings consistent with pneumonia. Duration of antibiotic therapy less than 5 days (minimum 3 days) in outpatients and admitted patients with nonsevere CAP who reach clinical stability is recommended, rather than ≥5 days of therapy. In patients admitted with severe CAP, the guideline recommend 5 or more days of antibiotics. Corticosteroids may be used in patients with severe CAP, but the guidelines recommend against their use in nonsevere pneumonia. This review summarizes the 2025 guideline recommendations with an emphasis on their impact on emergency medicine.