It can be hard to distinguish spasmodic croup from infectious croup, but spasmodic croup usually comes on suddenly.

Laryngotracheitis, laryngotracheobronchitis, laryngotracheobronchopneumonitis, and spasmodic croup are included in the croup syndrome.

Laryngotracheitis, laryngotracheobronchitis, laryngotracheobronchopneumonitis and spasmodic croup are included in the croup syndrome.

Both spasmodic croup and acute croup are more common in children with a family history of croup.

The risk of spasmodic croup may also be increased by a previous attack.