The methods of allergen detection in infants include the following two main categories: first, in vitro testing methods, that is, blood sampling to test the level of allergen-specific IgE in the child’s serum, this method is not affected by the child’s oral medication. The second is the in vivo test, which is a skin prick test. This method may be affected by the child’s oral antihistamines, hormones and other drugs, so before doing the skin prick test, the antihistamines and hormones and other drugs should be stopped for a period of time as required, and then do the skin prick test. The specific choice of which test method to choose depends on the child’s condition and clinical presentation. If necessary, both methods can be done at the same time, so that they can compensate for each other’s deficiencies.