For every family, the health of the baby is the top priority of the family. However, for babies within 1 week of age, food allergies can easily occur due to the imperfect barrier function of the mucous membrane of the gastrointestinal tract, which makes it extremely easy for foreign proteins to pass through, and due to immature immune function. Experts say that most allergies in infants and young children start with food allergies, which can cause eczema or multi-organ damage. Food allergy in infants is mainly manifested by eczema. 87% of infants with eczema within 1 year of age can find food allergy, especially newborns with milk protein allergy without effective intervention may further develop into allergic rhinitis and asthma when they grow up, so allergy prevention becomes more critical. In medical theory, when the human immune system overreacts to naturally occurring harmless substances from the air, water, contacts or food, it is believed that the human body has an allergy, and when individuals suffering from allergies are exposed to naturally occurring harmless substances that cause allergies, their immune system will produce a special antibody (LgE) and chemical substances released by mast cells (histamine ), which causes the symptoms of an allergic reaction. Experts say that the causes of allergies in babies may be related to genetics, intrauterine sensitization, immature intestinal barrier function, and dysbiosis of the intestinal flora. Food is the earliest exposure to infants, the main allergens, and food allergies, about 140 kinds of food can cause food allergies, 90% of food allergies and milk, eggs, soy, wheat, peanuts, fish, shrimp, nuts and other 8 kinds of food allergies, which, peanuts, nuts food allergies can last for years, even after adulthood. The foods that eczema babies are most allergic to include milk, eggs, soybeans, and wheat. Second, eczema is not the only symptom of allergy Many parents believe that the symptoms of allergy in babies are mainly manifested on the skin, as long as the skin appears eczema, that is allergy. Experts point out that this idea is wrong. There are many symptoms of food allergy: reaction in the mouth may cause oral allergy syndrome, edema or itching of the throat, lips and tongue; reaction in the gastrointestinal system, diarrhea, blood in the stool, vomiting, refusal to eat, reflux, constipation, abdominal pain; reaction in the skin, eczema, itching, rash, hives, edema, dryness; reaction in the respiratory system, wheezing, asthma The reaction in the respiratory system, wheezing, asthma, cough, rhinitis, etc., serious anaphylaxis can occur. Third, food allergies have crossover In addition, the allergens contained in food may have a certain degree of mutual crossover. Simply put, people who are allergic to one kind of food are also allergic to another kind of food because the two kinds of food contain the same allergen, which causes the same food allergic reaction to occur in different foods. For example, 92% of people who are allergic to cow’s milk may be allergic to goat’s milk, and 50% of people who are allergic to cod may be allergic to mullet, herring, or plaice.