Differentiation of tuberculous from nontuberculous cavitary lung disease

Tuberculous and nontuberculous cavitary lung disease is often initially misdiagnosed, delaying therapy. To identify findings which might help avoid such delays, we performed a retrospective review of all patients admitted to two community hospitals over a 6-year period for infectious cavitary disease of the upper lobe or apical segment of the lower lobe. 10 patients with tuberculosis and 16 with nontuberculous infections were identified. Delays in initiating therapy were common to both. Most signs and symptoms were nonspecific. The mean duration of symptoms was greater in tuberculosis (72 days) compared to nontuberculous infections (18 days). Putrid sputum was found only in nontuberculous infections (11/16). Roentgenographic features of fibronodular infiltration and atelectasis occurred only in tuberculosis. Air fluid levels were seen only in nontuberculous disease (10/16). Leukocytosis with immature neutrophils was found only in patients with nontuberculous cavities. We conclude that the previously described clinical, laboratory, and roentgenographic features may be useful in correctly diagnosing infectious cavitary lung disease.