Complications of Influenza B infection in a child with Down syndrome: a case report

Introduction. Down syndrome (DS) is characterized by a unique immunological profile that predisposes affected individuals to severe viral infections. Alterations in both innate and adaptive immunity, along with common comorbidities such as hypotonia and airway anomalies, heighten the risk of complications from pathogens like Influenza B. Case presentation. We report on the case of a 4-year-old girl with DS who developed acute respiratory failure secondary to Influenza B infection. Imaging and laboratory findings pointed out bilateral pneumonia with ground-glass opacities and elevated inflammatory markers. Treatment included high-flow oxygen, oseltamivir, corticosteroids, antibiotics, and supportive care. The patient showed gradual clinical improvement and was discharged in a hemodynamically stable condition. Conclusions. This case illustrates the increased risk of severe outcomes in children with DS during otherwise moderate viral infections. It underscores the need for early diagnosis, aggressive intervention, and routine Influenza vaccination in this vulnerable population to mitigate serious complications.