Abstract

A classic clinical and radiographic picture of Klebsiella pneumonia has emerged in the literature. Patients are typically male, older than 48 years, and have a history of chronic alcoholism. The majority of these pneumonias are community acquired. Bulging interlobar fissures and cavitation are radiographic findings said to be distinctive for Klebsiella pneumonia. We prospectively studied 15 cases of bacteremically proven Klebsiella pneumonia and found clinical and radiographic features strikingly different from those described in the literature. Immunosuppression (from corticosteroids, cytotoxic chemotherapy, neutropenia, hematologic malignancy, and transplantation) now rivals alcoholism as the primary risk factor. Cases tended to be nosocomial rather than community acquired. Neither bulging interlobar fissure nor cavitation was seen in any case. The right upper lobe was involved in 11 of our 15 cases. Pneumonia due to Klebsiella oxytoca was more likely to be isolated from patients with bilateral infiltrates, while Klebsiella pneumoniae was more likely in patients with unilateral infiltrates.