Which age group is most commonly affected by croup?

The age group most commonly affected by croup is children, typically those between the ages of 6 months and 3 years. Croup is a respiratory condition that causes swelling in the airways, leading to symptoms like a barking cough, stridor (a high-pitched wheezing sound), and difficulty breathing. It is primarily caused by viral infections, most often parainfluenza viruses, and young children's smaller airways make them more susceptible to the swelling that croup causes.

Adults, the elderly, and teenagers are less frequently diagnosed with croup because their airway anatomy is different and their immune systems and respiratory tracts are typically more developed and less reactive to the infections that lead to croup. Thus, the incidence of this condition is significantly higher in younger children, making them the most commonly affected age group.