Parainfluenza Bronchiolitis Mimicking Recurrent Lobar Pneumonia.

Human parainfluenza viruses (HPIVs) are the second most common cause of hospitalization in children, causing upper respiratory tract illness (URTI) and lower respiratory tract illness (LRTIs) in infants and young children. Common presentations include common cold, laryngotracheobronchitis (croup), bronchitis, and pneumonia. In immunocompetent adults, their effect is usually limited to mild upper respiratory tract illness with spontaneous recovery. However, elderly and immunocompromised adults are at risk for severe infection manifesting as epiglottitis, bronchiolitis, pneumonia, and on rare occasions, acute respiratory distress syndrome (ARDS). We describe a case of a 73-year-old female who developed recurrent respiratory distress and acute hypoxemic respiratory failure and was treated for bacterial pneumonia but was eventually diagnosed with severe parainfluenza bronchitis, causing mucus plug obstruction and lobar lung collapse.