There is nothing more disheartening than having atopic eczema/dermatitis and knowing that flares are triggered by a number of foods/household/beauty products, but after having a patch test done you are told by the Allergist that you are not allergic to anything.
The point is that whilst you may not have an allergy or a food sensitivity, both would show IgE antibodies in tests, but you may have an intolerance which do not trigger IgE antibodies.
The only way to truly identify intolerances - in particular those related to foods - is by following the elimination diet - previously discussed on this page. It is a tough programme to follow, but the beauty of it is that it may help identify true triggers and allow some foods to be reintroduced with no problem. A case of the true trigger causing hyper-sensitivity that then makes you react to a disproportionate number of things.