is less common than laryngotracheobronchitis and acute spasmodic croup. It progresses from an upper respiratory tract infection and may be confused with laryngotracheobronchitis because of similar manifestations. Treatment for laryngotracheobronchitis is not effective if the child has bacterial tracheitis.
The following discussion focuses on acute spasmodic croup and laryngotracheobronchitis, the most common types of croup leading to hospitalization.