This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
The most common etiological agent for acute bronchiolotis in infancy is: March 2011 
Select and explain. 
A. Influenza virus, B. Parainfluenza virus, C. Rhino virus, D. Respiratory Synctial virus
D: Respiratory Synctial virus
Answer: D: Respiratory Synctial virus 
Explanation: Ans. D: Respiratory Synctial virus Respiratory synctial virus is implicated in most cases of bronchiolitis Bronchiolitis: MC infective organisms: RSV and H. influenzae Mole common in boys Self limiting Chest X-ray shows: Hyperinflation with multiple areas of interstitial infiltration May lead to asthma in later life DOC: Ribavirin Oxygen is also helpful RSV immunoglobulins has no role in acute attacks Antibiotics are not used in initial phase