I can’t really give specific patient advice over the internet, of course, because I’m not your child’s doctor. In general terms, though, I’ve seen severe croup last a week or so. If it goes on much longer than that we start to wonder if there is something else inside the airway blocking airflow. The best way to check for that is with bronchoscopy — to actually have a look with a flexible tube with a light on the end that we can look through. I’m sure your child’s doctors are also thinking about that since it’s pretty standard. Croup also has a typical appearance through a bronchoscope.