People may be allergic to one or more food additives used in some
chocolate products.When such an allergy occurs,it may cause hives,swelling,itching,
sneezing and life threatening anaphylaxis.Chocolate contains milk,wheat/gluten,corn and corn syrup,nuts and various additives.If you are allergic to any one of them,you can show an allergic reaction to all the foods that contains the allergen even in minute quantities.
If you have an allergy to cocoa based foods can be found by allergy testing.