Asthma....

I have asthma. Andrew has asthma. Bethany has asthma. Andrew's asthma seems to get very worked up every time we go visit my parents. Different allergens that his lungs simply aren't used to and can't handle at this point. He seems to get sick almost every time we go there. I remember when I was a child, always getting sick when we went to visit my grandparents on the farm. The hay, dust, etc were/are my triggers. Andrew did have something else bugging him this weekend because he ran a fever off and on Saturday and Sunday. But no fever since Sunday. There was no school on Monday, so that is the day we traveled back home. Tuesday morning and he was still coughing to beat the band so I did keep him home from school that day, though he played most of the day and didn't act all that sick. Wednesday morning I sent him to school. I talked to the school nurse and she was going to give him his cough meds at lunch time. I also wrote a note to his teacher that asked that they encourage him to NOT RUN during gym and recess. I dropped him off at 7:45. All the students meet in the gym and stay there for their "Morning meeting" with the principal (at 8:00), she basically announces if there is anything special going on that day, they say the Pledge of Allegiance, etc... Then the Kindergarten classes go across the playground and yard to their building. Apparently Andrew was walking slower than his class and ran to catch up...guess what...ASTHMA and coughing. Lots of coughing. So much coughing in fact that his teacher said she couldn't teach over him. He had been in class for all of 15 minutes, coughing to beat the band, so they called and I had to go get him.
Yes, he is coughing. Yes, it gets REALLY bad when he runs around (that is why I warned them and asked that they remind him not to run...he ran, that was his mistake). But my question is...are asthmatics not allowed to come to school? If I keep him home every time he is having difficulties with his asthma he will be home for weeks at a time. Asthma is not contagious. No one is going to catch a cough from him. As long as we keep on top of him and don't let him get rowdy or run, he'll be fine. Yes, he will cough, but it will be under control. I even asked the nurse today when I took him in if she could suggest any stronger cough medication, she said only if we went to the doctor and they would prescribe a cough syrup with codeine...but that is for people with pneumonia, not asthma. So what am I supposed to do? I can't be there every second of the day to make sure he doesn't run. He'll learn as he gets older that his lungs just can't handle it. Any advice out there? Bethany's asthma doesn't seem to affect her nearly as much as Andrew's affects him. I'm just hoping and praying that they let him stay at school today!
Thanks for letting me rant...I just don't know what I'm supposed to do.