Ds has had croup many times - most times, yes, the barking cough lasted only one night. He usually gets it in addition to other things, i.e. colds, etc... I don't knoe about keeping them away from others - I don't think croup itself is contagious, just whatever virus may have caused it. One doctor even told us it could be brought on by his allergies. In my experience it passes pretty quickly - a couple days or so... If they are having trouble breathing though, get them to a doctor. Ds was rushed by ambulance to hosp. in Disney in the middle of the night because his airway was so constricted.