[A case of influenza B viral bronchopneumonia followed by CT]

A 69-year-old male with bronchial asthma was admitted to a hospital with fever, dyspnea, and productive cough. Arterial blood gas analysis revealed sever hypoxemia (PaO2 54.8 torr, PaCO2 28.8 torr). Chest roentgenogram showed diffuse reticulonodular shadows predominantly in the upper filed and a small amount of bilateral pleural effusion. CT image of the lung showed nodular opacities at the peripheral branches of the pulmonary arteries and bronchi, some of which had become confluent. The bronchoarterial bundle had become thicker compared with a CT taken 18 months before this admission. Three days treatment with antibiotics and gamma globulin did not change the symptoms or radiologic findings. After commencing methylprednisolone therapy, the pneumonia showed rapid improvement. Based upon the significant elevation of serum influenza B (B/Singapore/79) virus antibody titer, the patient was diagnosed as having influenza B viral bronchopneumonia. Twenty-three days after initiation of steroid therapy, slight nodular opacities were observed on CT. This finding suggests that bronchiolitis has a relatively prolonged course in influenza viral bronchopneumonia.