What is the most common age range for croup?

Croup is most commonly seen in children aged 6 months to 3 years. This age range is significant because the condition is primarily associated with viral infections that affect the upper airway and larynx, leading to inflammation and the characteristic barking cough and stridor. Young children have smaller airways, making them more susceptible to airway obstruction from such inflammation.

The immunologic competence and anatomical development of older children reduce their susceptibility to croup as they are more resilient to viral infections that cause the disorder. Therefore, children outside the 6 months to 3 years range are much less likely to experience croup as a result of their developed airways and enhanced immune systems. In summary, this age group is most affected due to a combination of physiological factors and the common viruses that trigger croup in early childhood.