As the organism can continue to be excreted from the respiratory tract for several weeks after the acute infection, isolation of the organism may not indicate acute infection. Hemolytic anemia has been described but is rare. A sputum Gram stain and culture usually is not helpful, except in excluding other pathogens. Radiographic findings are variable, but 4 distinct patterns have been described more frequently in mycoplasmal pneumonia. Bronchopneumonia often involves a single, lower lobe.
Lobar consolidation is rare.
Hilar adenopathy, which sometimes is mistaken for malignancy. A negative test does not exclude infection and this test may cross react with other pathogens, such as adenovirus, EBV, and measles. A quick bedside test can be performed by partially filling a purple top tube with blood and placing it in ice. All of these are used with acceptable sensitivity and specificity. In general, mycoplasmal pneumonia is a diagnosis that does not need emergency treatment.