Nonresolving pneumonia and mimics of pneumonia.

Physicians caring for patients with community-acquired pneumonia are often faced with the dilemma of how to approach a patient with slowly resolving or even nonresolving pneumonia. When the radiograph has failed to resolve by 50% in 2 weeks or completely in 4 weeks, the pneumonia should be considered to be nonresolving or slowly resolving. The causes of a nonresolving pneumonia and an approach to the work-up are presented.