My son had the Croup several times when we were living back in the U.S. One time he got it on vacation and it did get pretty bad very quickly (<24 hours), but it's not the norm. When it did get bad we took him to the ER at a Children's Hospital and they gave him some steroids via a nebulizer - within 30 minutes he was as good as new (seriously).

Thanks for the note that it's circulating here in Doha. . .ugh. . .as prone as he is to it I'm sure he'll end up contracting it.