It is common to be allergic to a food dye. There is a dye that I seem to react to but I haven’t figured it out yet. I just break out in hives every few Christmas seasons after eating some cookies. The best test for food allergies is usually trial and error. Stop eating the food, and the problem goes away… problem comes back when food is re-introduced. Of course this can take a while to figure out if you don’t know which food is causing the problem. There are some lab companies that will test for various food dye allergies. Sage systems is one and their website is: www.foodAllergyTest.com. While these tests are not perfect, they might be able to tell you which dyes are causing your child’s problems.