Ok first off typically croupe ends at age 5 the dr will tell you and usually everyone I talked to thats when their child's ended. However of course mine had it til age 8!! I did all the things you did the humidifier, the allergist, steam, cold air etc. He was allergic to alot of things mold, dust, dogs, etc. The allergist told us to have our house tested as it was through 2 floods. I noticed he would get it every time the season changed, it didn't have to be winter, it could be spring, summer, or fall, or winter. Eventually his body wouldn't even respond to the prednisone they gave him and he would just bounce off the walls with it and still have the same croupe. It got so bad that he would wake me in the middle of the night holding his chest saying mommy i can't breathe with what they call a strider cough, and off to the ER we would go where they would give him a steroid shot. Again this lasted til 8, but around that time I also left the house I was living in, I did see a remarkable difference in his health, so I do think there was mold in the house and it was contributing to this. Did your son go through the arm prick test for allergies or a blood test? If you need a good pediatric allergist I could recommend one to you, nationally recognized. He also treats my daughter who has severe tree and peanut allergy. Keep us posted ...
S.