A Case of Bronchiolitis Obliterans Organizing Pneumonia Associated with Pandemic Influenza (H1N1 2009)

Several types of influenza-related pneumonia have been reported. Bronchiolitis obliterans organizing pneumonia (BOOP) is a nonspecific lung injury. A 64-year-old man sought care to an emergency room due to breathing difficulties. He was diagnosed with pandemic influenza (H1N1 2009) by the real-time polymerase chain reaction (PCR) and was suspected of concomitant bacterial pneumonia. Therefore he was treated with oseltamivir and broad spectrum antibiotics. The disease progressed rapidly despite treatment, so a corticosteroid was added. The trans-bronchial lung biopsy was consistent with BOOP. Here, we investigated BOOP associated with the pandemic influenza (H1N1 2009) virus that was successfully treated with a combination of antiviral, antibacterial and corticosteroid drugs. Although BOOP associated with influenza is rare, combined disease should be suspected especially when the pneumonia does not response to antiviral agents and antibiotics.