Food allergy is a complex allergic disease in which the body’s immune system produces an overprotective immune response to certain foods that enter the body. Food allergens are antigenic molecules in food that can cause an allergic reaction in the body, mostly proteins, which can cause an allergic reaction (also called metaplasia) in the body. When the food allergens enter the body for the first time, the immune system of the allergic population treats these allergens as harmful substances and generates an excessive protective immune response against these substances, producing food-specific antibodies. When these antibodies come into contact with the food allergens again, the two will specifically combine, stimulating the body to release a large number of biologically active substances, prompting inflammatory reactions in the body’s effector organs and tissues, causing chronic symptoms and diseases in various systems, mainly involving the skin, digestive system, respiratory system and cardiovascular system, etc. In severe cases, this can lead to anaphylaxis. Patients with food allergy can be allergic to 4-5 or more foods at the same time, and the symptoms that occur when people are allergic to the same food vary from person to person. The former occurs mostly within 10 minutes to 2 hours after food intake, and most patients show skin symptoms, such as urticaria, pruritus, allergic purpura, angioneurotic edema, etc., which can also be accompanied by gastrointestinal reactions, such as vomiting and diarrhea. The latter mostly presents with digestive system symptoms, such as Wu’s unexplained long-term chronic diarrhea, irritable bowel syndrome, inflammation of the small intestine and colon, esophagitis, etc. The eight common allergenic food groups identified by the World Health Organization are wheat, peanuts, soy, nuts, milk, eggs, fish and crustaceans. As the incidence of food allergic diseases continues to rise worldwide, some common foods are also included in the tests, such as rice, wheat, crabs, tomatoes, corn, mushrooms, and meat. Among them, eggs and milk have the highest incidence of allergy. It is worth noting that sensitivities vary by disease and age, for example, milk is greater than eggs in the children’s group and eggs are greater than milk in the adult group. The clinical manifestations of food allergy can be easily confused with symptoms of other diseases. In addition to detailed medical and family history, it is most important to further confirm the diagnosis with relevant tests. Traditional testing methods include skin prick test, oral provocation test, and serum specific IgE antibody assay. Among them, serum specific IgE antibody assay is highly specific, safe and rapid in the diagnosis of food allergy, and can detect the IgE concentration of multiple antigens and their changes at the same time, so it is more commonly used in clinical practice. The mechanism of food allergy involves multiple factors such as age, race, occupation, environment, and genetics, etc. So far, avoidance or restriction of allergenic foods is the generally accepted prevention and treatment method. In addition, breastfeeding is promoted, and it is recommended that mothers should avoid foods that can cause allergies during pregnancy. Although food allergies are small, they are closely related to people’s quality of life, and even life-threatening in serious cases, so please raise your awareness and exclude your sensitive food allergens as soon as possible, so that you can live a good life together.