A 2-year-old child develops acute respiratory distress. 0/E breath sounds are decreased with wheeze on right side. Chest X-ray shows diffuse opacity on right side--Most probable diagnosis:

Foreign body aspiration is a very common problem in pediatric age group (< 4 years). In the question, child is presenting with sudden onset respiratory distress and there is U/L decreased breath sounds + U/L wheezing and on chest X-ray a diffuse opacity is seen on right side i.e. there is clinical and radiological evidence of bronchospasm and collapse suggestive of a foreign body in bronchus