Plastic Bronchitis Associated With Influenza a Virus in a Child With Nephrotic Syndrome

BackgroundPlastic bronchitis (PB) combined with nephrotic syndrome (NS) is rare, and the pathophysiological relationship between PB and NS has not been elucidated. We report a case of an 8-year-old boy with life-threatening PB caused by an influenza infection during a relapse of NS. Case presentationThe patient was on immunosuppressive drugs for NS. He developed fever due to an influenza A virus infection, followed by respiratory distress and frequent vomiting. Prednisolone was administered for possible bronchial asthma and NS. His respiratory status deteriorated rapidly, which required ventilator management. A large mucus plug was aspirated using bronchoscopy. He was then diagnosed with PB caused by the influenza A virus. Increased lower airway secretion and fluid leakage into the airways by relapse of NS were considered the causes of mucus plug formation. Besides, the decreased circulating blood volume might have made the bronchial secretions viscous with cast formation.ConclusionsPediatric patients with NS may be at a higher risk of developing PB. As PB is a life-threatening condition, patients with NS should be closely monitored when simultaneously infected with influenza virus.