A child with three days history of upper respiratory tract infection presents with stridor, which decreases on lying down postion. What is the most probable diagnosis -

Ans. is 'b' i.e., Laryngotracheobronchitis This child has : - i) 3 days history of upper respiratory tract infection. ii) Followed by stridor These features suggest the diagnosis of croup. Clinical manifestations of Croup Most patients have an upper respiratory tract infection with some combination of - Rhinorrhea Pharyngitis Mild cough Low grade fever o After 1-3 days signs and symptoms of upper respiratory tract obstruction become apparent - Barking cough Hoarseness Inspiratory stridor