Skin testing isn't too bad. THe worst part is keeping them from trying to scratch their back, etc.
Liam had a positive test result to egg, then nothing else was positive, but after the time limit was up, all of his other known allergens plus shellfish (never had it lol) popped up. Allergist didn't know what to make of it, only called egg positive, but told me to treat him like he was allergic to the rest (all of the top 8 except fish, he is no longer allergic to milk, the testing was a year ago.)
He recently had RAST done and everything was negative. He reacts w/ hives to soy and skin contact to peanuts, so those at least are definite IgE allergies. He had accidental egg exposure last week. I don't think he actually swallowed any, I finger swept his mouth (bite of pancake) but he got horrible eczema, no hives. Weird.
Anyway, my point is neither test is completely accurate. Elimination diets are the only way to figure out food allergies for sure.