Which finding suggests bacterial pneumonia?

• A. Cough with purulent sputum
• B. Shortness of breath on exertion
• C. Fever and crackles
• D. Chest pain with deep inspiration

Answer: (C)

In bacterial pneumonia, infection settles in the lung tissue and causes alveolar air spaces to become filled with inflammatory exudate, leading to consolidation. This produces two classic signs: fever, which reflects the systemic infection, and crackles on auscultation, which result from air trying to move through fluid-filled or consolidated areas of the lung. The combination of fever and crackles directly points to lung involvement from an infection, making it the best clue for pneumonia. Coughing up purulent sputum can occur with other respiratory infections as well and isn’t as specific; shortness of breath on exertion and pleuritic chest pain can appear in many conditions, but fever with crackles most clearly signals pneumonia.