A 25-year-old male presents with sudden onset of high fever, cough with rusty sputum, and chest pain that is worse with deep breathing. On physical examination, there is decreased breath sound and dullness to percussion on the left lower side of the chest. What would you suspect, and what are the next steps?
The patient's symptoms are suggestive of lobar pneumonia, possibly caused by Streptococcus pneumoniae, which is known to cause 'rusty' sputum. To confirm the diagnosis, a chest X-ray should be performed to look for lobar consolidation. A sputum culture can be obtained to identify the causative organism, and blood tests including complete blood count and inflammatory markers should be ordered. The patient should be started on empiric antibiotic therapy, typically a beta-lactam antibiotic, while awaiting culture results.