Community-acquired pneumonia: new outpatient guidelines based on age, severity of illness.

Pneumonia is a common and important infectious disease in all age groups but especially in the elderly. Mortality and morbidity are quite high when associated with certain risk factors such as comorbid medical conditions and clinical features that implicate more severe disease. In the absence of such features, patients can be treated quite safely out of the hospital, as long as followup and compliance issues are not a problem. Therapy should be directed toward gram-positive and gram-negative aerobic bacteria and, at times, be further expanded to cover atypical organisms such as Legionella sp. Appropriate antimicrobial agents are those that not only cover expected microorganisms but are compatible with each patient's existing medical regimen.