Diagnosing and treating influenza in the emergency department: an evidence-based update.

Influenza is a common emergency department presentation that can cause serious complications, particularly in young children, older adults, pregnant and postpartum patients, and patients with underlying conditions. Because its clinical features overlap with those of other respiratory illnesses, emergency clinicians must determine when testing will inform care, which patients need prompt antiviral treatment, and who can be safely discharged. This review presents evidence-based recommendations for the evaluation and management of influenza in the emergency department, with attention to diagnostic testing, antiviral selection, complications, disposition, and common risk management pitfalls.