Croup

Croup (also called laryngotracheobronchitis) is a disease which afflicts infants and young children, typically aged between 3 months and 5 years. It is characterized by a harsh 'barking' cough, inspiratory stridor and fever.

It is most often caused by parainfluenza virus, but other viral and bacterial infections can also cause it. It is the body's reaction to the infection that causes the respiratory distress, not the infection itself. It usually occurs in young children as their airways are smaller and differently shaped than adults, making them more susceptible. There is some element of genetic predisposition as children in some families are more susceptible than others.