Most common organism causing laryngotracheobronchitis is: (A) RSV, (B) Para-influenza virus, (C) Influenza virus, (D) H. Influenza
Answer is B. Para-influenza virus I and II is the most common organism causing laryngotracheobronchitis. Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 328