Snapshot An 18-year-old college student presents to the student health clinic with a mild fever, headache, fatigue, and a dry, non-productive cough. He says that his symptoms started about 3 weeks ago and have not improved. The physician obtains a chest radiograph, which shows a pattern of diffuse interstitial infiltrates that appears worse than the patient’s physical appearance. The patient is prescribed azithromycin for his infection. Introduction Classification login to view 5 more bullets Epidemiology login to view 7 more bullets Pathogenesis login to view 3 more bullets Associated conditions login to view 4 more bullets Presentation Symptoms login to view 3 more bullets Physical exam login to view 3 more bullets Imaging Chest radiography patchy or diffuse interstitial infiltrates chest radiograph often looks more severe than the patient’s actual presentation Studies Labs login to view 2 more bullets Microbiological studies login to view 2 more bullets Making the diagnosis login to view 1 more bullet Differential Viral infection login to view 2 more bullets Chlamydophila pneumoniae infection login to view 2 more bullets Legionella infection login to view 4 more bullets Treatment Medical login to view 3 more bullets Complications Autoimmune hemoltyic anemia Acute interstitial nephritis Bacterial myocarditis