Can you have allergic reactions to fats (i.e.margarine,etc.) and/or sugars??? When I eat foods containing margarine and/or sugars,(not sure which it really is) I turn red from neck down along w/hives all over. It's always same pattern, hands itch, facial and then entire body. Through elimination of foods, I've narrowed it down to possibly the margarine,and/or butter. Is this possible??? All my allergy tests have been negative.