Plastic Bronchitis Associated with Influenza.

A 5-year-old boy was admitted to our hospital due to rapidly progressive respiratory failure. One day before admission, he visited his primary physician with symptoms of fever, rhinorrhea, and cough. Pneumonia was diagnosed from a radiograph of the chest showing an infiltrative shadow in the left lower lung field (Figure 1). An oral antibiotic was prescribed. However, the patient returned the next day because of respiratory distress and chest pain. His physical examination was notable for a temperature of 39.2°C, respiratory rate of 30 breaths/min, oxygen saturation of 90% on room air, and decreased breath sounds in the left lung. Radiograph of the chest revealed atelectasis of the entire left lung and tracheal deviation to the left (Figure 2).Figure 2Radiograph of the chest on the following day demonstration atelectasis of the entire left lung and tracheal deviation to the left.View Large Image Figure ViewerDownload Hi-res image Download (PPT) The patient was intubated and bronchoscopy was performed. The left upper and lower bronchi were obstructed with dense mucous casts, confirming the diagnosis of plastic bronchitis (Figure 3). Immediately after removing the bronchial casts (Figure 4), his respiratory condition improved, and he was extubated 2 days later. Nucleic acid extracted from the cast was positive for influenza A (H1N1pdm09) by real-time polymerase chain reaction. He had not received the influenza vaccine that season due to a history of an extensive local reaction.Figure 4Cast removed from the left upper and lower bronchi.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Plastic bronchitis is a rare medical condition characterized by rapidly progressive respiratory failure due to mucous casts that fill the airway, which can be fatal. Plastic bronchitis in children is reportedly caused by congenital heart diseases, asthma, or infection, the latter particularly by the influenza virus.1Rubin B.K. Plastic bronchitis.Clin Chest Med. 2016; 37: 405-408Abstract Full Text Full Text PDF PubMed Scopus (43) Google Scholar The mechanism and risk factors of plastic bronchitis related to influenza are not clear. Some reports state that patients with plastic bronchitis associated with influenza have a history of allergy or serious adverse reaction to influenza vaccine, suggesting involvement of immune responses to components of the influenza virus.2Uchimura T. Mori M. Nariai A. Yokota S. Analysis of cases of severe respiratory failure in children with influenza (H1N1) 2009 infection in Japan.J Infect Chemother. 2012; 18: 59-65Abstract Full Text PDF PubMed Scopus (10) Google Scholar,3Uda K. Shoji K. Koyama-Wakai C. Furuichi M. Iwase N. Fujisaki S. et al.Clinical characteristics of influenza virus-induced lower respiratory infection during the 2015 to 2016 season.J Infect Chemother. 2018; 24: 407-413Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar Although the administration of steroids or antiviral drugs has been suggested, previous case reports also have shown that removal of casts is needed to improve respiratory status.1Rubin B.K. Plastic bronchitis.Clin Chest Med. 2016; 37: 405-408Abstract Full Text Full Text PDF PubMed Scopus (43) Google Scholar,4Deng J. Zheng Y. Li C. Ma Z. Wang H. Rubin B.K. Plastic bronchitis in three children associated with 2009 influenza A (H1N1) virus infection.Chest. 2010; 138: 1486-1488Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar,5An H.Y. Baek S.M. Choi Y.Y. Kim Ys Lee E.J. Choi Y.H. et al.A case of plastic bronchitis associated influenza a pneumonia requiring ECMO assistance.Pediatr Infect Vaccine. 2018; 25: 101-106Crossref Scopus (1) Google Scholar