Eczema babies often have genetic allergies, which means that there is a tendency to develop eczema, asthma and allergic rhinitis in the family; they are prone to allergic reactions to allergic proteins; and they often have elevated serum IgE and increased blood eosinophils. Therefore, external allergens can contribute to eczema. Allergens are classified as food allergens and inhalant allergens. Common food allergens include eggs, milk, peanuts, wheat, soybeans, fish and shrimp. Inhaled allergens include dust mites, animal dander, mold spores and pollen. Allergen testing is a specific IgE test for these food or inhalant allergens, and there are two commonly used tests, the skin prick test and the blood test. The skin prick test is quick and easy and inexpensive, while the blood test is not affected by the severity of the rash or the medication used but is more expensive and usually requires a jugular vein for babies under one year of age. Doctors and parents can choose the test according to the situation. Infants too young to have been exposed to possible allergens and have not yet developed the appropriate immune response may produce false negative results. Eczema can be relieved by avoiding suspected allergens in eczema babies. Early eczema in particular is closely related to food allergy. Babies with moderate to severe eczema who do not do well with conventional treatment should be highly suspicious of milk protein allergy, and once diagnosed, need to avoid regular formula and replace it with special formula that can significantly improve eczema. Some parents will follow their own experience and strictly abstain from certain foods, which can cause malnutrition in their babies. Allergen testing can clarify whether your baby is allergic to these foods, and if the test results are negative, you can try eating these foods to avoid unnecessary abstinence. Research has proven that as babies grow up, allergy to food will gradually decrease, while allergy to inhalation will gradually increase, therefore, it is recommended that eczema babies be rechecked for allergens six months to a year.