Abnormal reactions caused by eating a normal food, such as urticaria, eczema, asthma, allergic rhinitis, angioedema, dermatitis, abdominal distension, diarrhea or abdominal pain, migraine, etc., and these reactions are only in Some sensitive people occur, known as food allergies (Food allergy or Food hypersensitivity). The mechanism of food allergy is related to abnormal immunity (especially IgE antibody). There is also a situation similar to food allergies, called food intolerance (Food intolerance, also known as food intolerance), is also due to an abnormal reaction caused by eating a certain normal state of food, its performance is similar to food allergy, and it is also related to some people''s special physique, but its mechanism is not related to immune mechanism The most typical example is milk lactose intolerance. In actual work, it is difficult to distinguish between food allergy and food intolerance. Some people collectively call them "adverse reactions to food" (adverse reaction of food). Others simply refer to both cases as food allergies, causing great confusion in the concept.

　　 1999 No. 23 of the Codex Alimentarius Commission The meeting released a list of common allergenic foods, and believes that more than 90% of allergic reactions (which may also include food intolerance) in the world are clinically caused by eight types of food:

　　①milk, especially milk;

　　②poultry eggs;

　　③fish (including marine fish and freshwater fish);

　　④Crustacean aquatic animals (shrimp, prawn, crab, lobster, clam, etc.);

　　⑤peanut;

　　⑥soybean;

　　⑦nuts (Almonds, walnuts, cashews, hazelnuts, pine nuts, chestnuts, etc.);

　　⑧wheat.

　　People who are allergic to a certain food should try to avoid eating this kind of food. At the same time, (because food allergies often have a crossover phenomenon), pay attention to the above allergenic foods and observe the eating of these foods closely. After the reaction.

　　Allergic foods are not clearly defined, but those with allergic reactions mentioned above often, in addition to closely observing the reaction after eating these foods, food allergy testing can also be carried out, including "food allergen screening test" (IgE test ) And the "lactose hydrogen breath test", the former is for food allergies and the latter is for lactose intolerance.