There are three main methods of allergen testing: food provoked avoidance test, skin test, and serum specific IgE test. 1. Food-activated avoidance test: After consuming a certain food, the child is suspected to have allergic symptoms. If the child’s allergic reaction disappears after avoiding the food, and if the allergic reaction occurs again after trying the food for 3 months, it is basically certain that the food can cause allergy in the child. 2. Skin test: Puncture the baby’s epidermis with a small needle and inoculate with an appropriate amount of the suspected allergic substance. Check whether the local skin becomes red and swollen, so as to determine whether the child is allergic to the inoculated material and the degree of allergy. 3. Serum specific IgE test: Includes the level of total IgE and specific IgE in the body. The level of total IgE in the body represents the total level of allergy, but is not specific. Specific IgE level can accurately reflect to a certain substance, the test result shows that a high level of IgE of a certain substance indicates that the baby is allergic to that substance.