Allergen blood tests are available in a variety of combinations, with settings varying from one testing organization to another, and are generally capable of detecting 14-20 allergens. Currently the test is mainly divided into inhalation and contact groups according to common allergenic substances. The inhalation group mainly contains beef, lamb, pork, barley, milk, fish, seafood, tomatoes, wheat, corn, eggs, soybeans, mushrooms, etc.; and the contact group includes household dust mites, house dust, cockroaches, cat dander, dog dander, mixed grasses, trees, mold combinations and pollen combinations. Blood test is mainly through the combination of solid allergens to capture the antibodies in the blood sample to complete the test, due to the existence of cross-reaction has the possibility of producing false-positive results, undetected allergic substances may not be completely excluded, need to be combined with life experience and other tests such as skin prick test to make a comprehensive judgment.