A Case of Adult Respiratory Distress Syndrome due to Pasteurella Pneumonia in a Patient Undergoing Tocilizumab Treatment for Rheumatoid Arthritis

A 58-year-old woman undergoing tocilizumab treatment for rheumatoid arthritis was admitted to our hospital with acute dyspnea. She worked in a dairy farming. Chest computed tomography revealed extensive heterogeneous ground-glass opacities and infiltrative shadows in both lungs. Her respiratory condition rapidly deteriorated, progressing to acute respiratory distress syndrome (ARDS). Laboratory analysis of her bronchoalveolar lavage fluid identified numerous Pasteurella species, thus giving a diagnosis of ARDS caused by Pasteurella pneumonia. With appropriate treatment, she recovered and was discharged after 30 days of hospitalization. Pasteurella species may cause skin infections following animal bites or scratches, and can further deteriorate to severe respiratory infections in immunocompromised individuals. Therefore, Pasteurella might be a potential etiologic agent of pneumonia in immunocompromised patients under certain circumstances.