What age group is most commonly affected by croup?

Croup is a common respiratory condition primarily affecting young children, particularly those between the ages of 6 months and 3 years. This age group is particularly vulnerable due to the anatomical and physiological characteristics of their airways, which are smaller and more easily obstructed than in older children or adults. In this age range, children are also more likely to experience viral infections, such as those caused by parainfluenza viruses, which are the leading cause of croup.

The presentation of croup often includes a distinctive barky cough, hoarseness, and stridor, particularly when the child is agitated or upset. While older children and even infants can get croup, the incidence and severity tend to decrease as children grow older and their airways mature. Infants under 6 months are less commonly diagnosed with croup, and children older than 3 years generally experience milder cases or other conditions that mimic croup but do not fit the classic presentation as closely. Thus, the 6 months to 3 years age group is primarily recognized as the most affected demographic for croup.