Lemonade?

This is not final, but lemonade? Last night we gave Johnny yellow lemonade and he had an asthma attack. At church he got yellow lemonade and had an asthma cough. I attributed these attacks mistakenly for the corn syrup before. I also attributed his nightly dust/dust mite attacks wrongly to the corn syrup from candy he'd eat after dinner. We have food challenged corn and wheat to maximum doses and seen no sign of any allergic reaction. It has got to be the lemonade! I am going to have the food allergist verify this for me.