Post-infectious bronchiolitis obliterans in children after the end of the COVID-19 pandemic.

Post-infectious bronchiolitis obliterans in children after the end of the COVID-19 pandemic.To the Editor, Bronchiolitis obliterans (BO) is a rare disease in which the main characteristic is chronic obstruction of the small airways.Post-infectious is the most common cause in children, mainly due to adenovirus (ADV), followed by other viruses such as respiratory syncytial virus (RSV), influenza or parainfluenza.Histologically, inflammation and fibrosis of the terminal bronchioles occurs, with total or partial obliteration of their lumen.The diagnosis of post-infectious bronchiolitis obliterans (PIBO) relies on a compatible clinical history of previous respiratory infection, usually severe, followed by chronic symptoms such as cough, tachypnea, intercostal retractions, hypoxemia and/or pathological auscultation with bilateral or unilateral fine crackles.Computed tomography (CT) of the lungs shows signs of mosaic perfusion pattern, with or without bronchiectasis, and pulmonary function tests with fixed airflow obstruction 1 .Treatment consists of a combination of anti-inflammatory drugs, oxygen therapy, bronchodilators, respiratory physiotherapy and antibiotics in case of acute infections 2 .