I'm hoping someone can give me a quick rundown on the difference between a food allergy and a food intolerance. 2yo DS has known issues with dairy and nuts. He'll have a reaction even if it's something I eat and is then passed to him through breastmilk. His "reaction" is a red ring with a some raised areas around his anus, loose/foul smell bowel movements, trouble sleeping and out of control hyperactivity bordering on aggression.
He has an appointment with an allergist scheduled for Monday. In preparation of that his pedi (who's previously been dismissive of the food issues) offered to write a lap slip to have blood testing done for the food allergies. The results of that were all absent/undetectable for every single category.
I remember reading a difference between IgE and IgA but I don't remember what that means. Could he have allergies that are digestive reactive instead of immune system? Or is that simply a food intolerance not allergy? Would that type of "allergy" show up on a skin prick test?