The development of many allergic diseases is related to contact with allergens. Therefore, allergen testing of patients with allergic diseases to find the real cause of allergy triggering can lead to targeted prevention and treatment. In clinical practice, the occurrence and development of many skin diseases are related to contact with allergens. Most patients with allergic diseases are usually treated to alleviate the symptoms without finding the real cause of the allergy, thus failing to do targeted prevention and treatment, resulting in repeated aggravation of the condition and prolonged treatment. Therefore, it is recommended that patients with frequent allergies should undergo an allergen screening test to find out whether the allergic reaction is caused by contact, ingestion or inhalation allergens, so as to solve the problem at its root. Never treat allergy as a minor problem and neglect the examination and treatment, which will eventually lead to serious consequences. An enzyme immunoassay is used to detect allergens quickly, accurately and painlessly. The method can qualitatively and quantitatively detect allergens (total IgE, total IgG, specific IgE, etc.) in the patient’s serum or plasma.IVT is used to detect IgE-mediated rapid-onset allergic reactions, which are distinctly seasonal, with short onset times and high morbidity rates. This test solves the difficulty that conventional skin tests are not suitable for detecting allergens during the attack period of patients with type I allergic reactions.FIgG is used to detect late-type allergic reactions. The reaction is mainly food-related, i.e. food intolerance. It is characterized by the development of relevant symptoms a few days or a week after exposure to the allergen. These allergic reactions are often misdiagnosed due to lagging symptoms and clinically manifest as chronic symptoms in various systems. If the long-term cause of the disease is unknown, recurring attacks, and prolonged treatment, it is recommended that food IgG should be checked. Allergen screening test adapted to the crowd: patients with unknown causes of allergies, eczema, urticaria, allergic rhinitis, asthma, psoriasis and other patients should do allergen testing, which is a great help in the prevention and treatment of disease. Allergen testing kits currently used by hospitals can be broadly categorized into the following: 1, screening test for inhalant allergens; 2, screening test for ingested allergens; 3, inhalant allergen classification test (this kit can detect specific inhalant substances that cause allergic reactions such as dust mites, pollen, etc.); 4, ingested allergens classification test can also detect specific allergy-causing foods). Allergens need to check the serum: including the following items: house dust mite / dust mite (Dx), dwarf ragweed / artemisia (Wx), cat dander / dog dander (E1 / E5), cockroaches (I6), Penicillium chrysogenum / Aspergillus fumigatus, etc. (Mx1), Cypress / Elm / Sycamore / Willow / Poplar (Tx4), lawn mow (W22), egg white / egg yolk (F245), milk (F2), fish, shrimp and crab (Fcru). Fish, Shrimp and Crab (Fcru), Beef and Lamb (Fmea), Cashews Peanuts Soybeans (Fnut), Mango (F91), Wheat (F4), Total IgE (IgE). Food allergens: beef, chicken, cod, corn, crab, egg white yolk, mushrooms, milk, pork, rice, shrimp, soy, tomatoes, wheat. Egg white yolk is highly sensitive (++++), milk is moderately sensitive (++), pork is hypersensitive (+); Misconceptions of Allergen Testing Allergen Blood Tests Generally, serum should be separated from red blood cells first, and serum plus allergen sample reagents should be used to test the final results. Generally, the test for food intolerance may take 3-4 hours to complete and the test for rapid onset of allergy with uniCAP may It takes about one day to complete the test for food intolerance, while the uniCAP test for rapid reaction of allergy may take about one day, and not about half an hour to get the result as some organizations said. This kind of uniCAP test which gets the result in half an hour does not separate the serum from the red blood cells, and it directly reacts to the allergy reagent to alleviate the operation cost, which affects the accuracy of the final test. Various methods of allergen testing Prick test for allergens Prick test can be regarded as a special kind of intradermal test, and it is an in vivo allergen detection method that is currently respected internationally, especially in Europe and the United States. Because it is only one ten-thousandth of the skin prick liquid of intradermal test, it is safe, sensitive and accurate, and has gradually replaced the traditional intradermal test due to the characteristics of small skin lesions and painlessness of the patient, just like a mosquito bite. Principle: When there is a certain allergen into the skin, some substances have a rapid-type allergic reaction to the patient, immediately and specifically caused by the mast cell degranulation of the skin, the release of histamine and other active substances, resulting in local capillary dilatation (erythema), increased permeability of the capillaries (edema, doughnuts), a positive person said to be allergic to the antigen. Methods of operation: first, put a drop of puncture skin test solution on the skin, and then use the puncture needle to pass through the drop and gently pierce the skin. Plaque test Plaque test has been used for a hundred years, the reliability of the diagnosis of contact dermatitis and certain allergic dermatoses has been fully proved, promoting the development of contact dermatitis and skin allergy detection. Generally, European standardized test reagents are used, and the test is accurate. Principle: Apply the suspected sensitizing substance to the patient’s skin, enter the body through the skin or mucous membranes, and then the antigen-presenting cells present the antigen to the T-lymphocytes, so that the specific T-lymphocytes are activated, and the inflammatory reaction is induced. Indications: 1, contact dermatitis, eczema, occupational dermatosis and other skin diseases occurring as a result of metamorphic reactions caused by exposure to certain substances. 2, when the cause of the disease is unknown or there are several kinds of material contact, need to find the cause of the disease, can do patch test. Specific method: Put the reagent on the skin and observe for a period of time, and then judge whether you are allergic to the substance according to the skin’s reaction to the contact material. Types of test: 1, nickel sulfate: a variety of metals and gold-plated items; 2, lanolin alcohol: a variety of ointments, creams, skin care products and soaps; 3, neomycin sulfate: topical antibiotic creams, skin lotions, ointments, eye drops and ear drops; 4, potassium dichromate: cement and a variety of chemicals; 5, kainic acid mixture: a variety of topical anesthetics; 6, spice mixtures: cosmetics, fragrances and flavoring products; 7, Rosin: adhesives, sealants; 8, epoxy resins: adhesives, surface coatings and paints; 9, quinoline mixtures: certain drug-based cold creams, ointments, creams and bandages; 10, Peruvian balsam: a variety of cosmetic agents, perfumes, and cough syrups, cough syrups, chewing gums and confectionery confections; 11, ethylenediamine dihydrochloride: stabilizers, emulsifiers, and topical germicides/antibiotic creams/eye drops and nose drops; 12, chloride: gold-plated items and artificial jewelry; 13, p-tert-butylphenol formaldehyde resin: leather products, furniture and shoe industry waterproof adhesive; 14, aromatic mixtures: cosmetic agents, dermatological topical creams and bandages; 15, carbolic mixtures: rubber products, pesticides, and some glues; 16, carbon black rubber mixtures: tires, handles, and water hoses; 17, CL + ME isothiazolinone: a variety of shampoos, creams, skin lotions and other skin care products; 18, quart-15: creams, skin lotions, shampoos, soaps and in fact cosmetic agents and skin care products; 19, mercaptobenzothiazole: a wide range of rubber products, adhesives and industrial antiseptics; 20, p-phenylenediamine: permanent and non-permanent hair dyes; 21, formaldehyde: a wide range of building materials and the plastics industry; 22, mercaptobenzothiazole mixtures: A wide range of rubber products such as shoes, gloves and rubber bands; 23, thimerosal: some cosmetic agents, nose drops and ear drops; 24, colchicine mixtures: almost all rubber products. Total IgE test Total IgE test is a test to determine the body’s allergy. When it is elevated and there is no parasitic infection, it indicates that the patient is being sensitized. Food intolerance It has been clinically proven that many chronic diseases are food related and the symptoms disappear after removing the problematic food. The food intolerance test is also the only delayed reaction (IgG) test for food allergies. Chronic symptoms such as diarrhea, mouth ulcers, hives, acne, migraines, easy fatigue, depression, shortness of breath, sleep disorders, teeth grinding, etc., all of which should be tested for food intolerance if no cause can be found, may be related to food intolerance. UniCAP test The UniCAP automatic in vitro diagnostic system developed by the Swedish company Farmacia is currently the most advanced laboratory system for checking allergens in the world, and has been confirmed by the International Committee for Clinical Laboratory Standards. It has been recognized by the World Health Organization for its high safety, accuracy and reliability, and is known internationally as “the gold standard for allergen testing”. Principle: Allergens are covalently bound to CAP’s cellulose solid-phase carrier and react with specific IgE antibodies in the patient’s serum sample. A standard curve is drawn based on the World Health Organization (WHO) IGE reference material and the IgE concentration in the sample can be deduced from the fluorescence intensity. Test types can detect more than 600 allergens including inhalation and food. A simple blood sample collection provides fast and accurate results, and the degree of allergy can also be detected. As the test is accurate and can quantitatively measure the degree of allergy, it greatly reduces human error and guarantees the credibility of the test results, providing a reliable basis for doctors’ clinical treatment.