Aspiration pneumonitis is best described as what?

• A. Chemical injury by acidic gastric contents
• B. Bacterial infection by anaerobes
• C. Viral infection
• D. Allergic reaction

Answer: (A)

Aspiration pneumonitis is a chemical injury to the lungs caused by aspirated gastric contents, especially acidic fluid. The acid and irritants burn the airway and alveolar surfaces, provoking inflammation and edema without an initial infection. This explains the sudden onset after an aspiration event and why antibiotics aren’t routinely used unless a secondary bacterial infection develops. It’s distinct from aspiration pneumonia, which is an infectious process (often involving anaerobes) with fever and a different clinical course. Viral infection or an allergic reaction don’t describe the underlying mechanism here, which is chemical injury from acidic gastric contents.