Mycoplasmal pneumonia. Three severe cases of a common infection.

Mycoplasma pneumoniae is one of the most common causes of community-acquired pneumonia. Infection is usually self-limited, but fulminant pneumonia and extrapulmonary complications can supervene. Usually, unilateral confluent, patchy, or nodular infiltrates of the lower lobe are seen on roentgenograms. Diagnosis is achieved by isolation of the organism or by serologic methods. Treatment with either erythromycin or tetracycline is effective, although organisms can be recovered during therapy. In the three cases of mycoplasmal pneumonia reported here, infection was resistant to initial therapy but patients recovered when appropriate antimicrobial therapy was instituted.