An Uncommon Case of Secondary Organizing Pneumonia Due to Influenza Type B

Secondary organizing pneumonia refers to a disease process caused by pulmonary tissue injury. Various insults can cause secondary organizing pneumonia, including multiple types of infections and cancer. The mainstay of diagnosis is a combination of imaging and lung biopsy showing inflammatory changes, specifically plugs with granulated tissue and fibrosis. Clinical suspicion needs to be raised for secondary organizing pneumonia when a patient is requiring increasing amounts of oxygen in the presence of treatment for pneumonia or another underlying lung disease. Here, we present the case of a 65-year-old male who presented with acute hypoxemic respiratory failure in the setting of previously having been tested positive for influenza B. Aggressive steroids with eventual tapering of his O₂ requirements led to a successful outcome. While influenza has been reported as a cause of secondary organizing pneumonia after proceeding infection, these cases are usually represented by type A, rather than B.