I tried a wheat product

I tried a cookie made with wheat and no other ingredients that Nathan is allergic too - I didn't like what I saw. Nathan ate it and then started crying and trying to gag him self. He said it was "stuck in his teeth" to a 3.5 year old this could mean anything. I was freaking out, was he having a reaction??? There was no salt, why was he doing this?? I rushed to give him some Benadryl and he was fine. This was scary, I didn't like what I saw.