Bronchiolitis primarily affects children in which age range?

• A. Under 6 months
• B. Under 2 years
• C. Under 1 year
• D. Under 5 years

Answer: (B)

Bronchiolitis is a viral infection of the small airways that most commonly affects very young children. Because infants have smaller, more easily obstructed airways, inflammation and mucus production lead to breathing difficulties early in life. The typical age range is children younger than two years, with the majority of cases in the first year. That makes under two years the best descriptor. While it can occur in infants as young as a few weeks, and up to nearly two years, it becomes much less common after two. The other options either miss younger children who can be affected or include ages where bronchiolitis is much less typical.