Allergic diseases are common diseases that can directly affect the quality of life and can even be life-threatening in severe cases. Common allergic diseases include asthma, allergic rhinitis, allergic dermatitis, and drug allergies. Blackley, a British doctor, has predicted that “with the development of civilization and education, this disease will become more common than it is today.” This year, July 8 is “World Allergy Day”. The prevention and treatment of allergic diseases from the details of life should be said often. Common allergens can be broadly divided into airborne allergens, food allergens and contact allergens. Common airborne allergens (airborne allergens) include pollen, dust mites, mold and so on. Pollen is actually the male germ cells of flowers, whose role is equivalent to that of human sperm, and includes airborne pollen and insect-borne pollen. Airborne pollen is small and light, and can stay in the air for a long time and drift around with the wind, with the chance of being inhaled into the airways, thus easily causing allergies. The pollen of insect-borne flowers is large and heavy, and does not easily disperse into the air. It requires the medium of insects to spread, and has less chance of exposure through the respiratory tract, so it is less likely to cause allergies. Allergies caused by pollen are called hay fever or chytridiomycosis. Hay fever is one of the most common allergic diseases. Symptoms are nasal itching, sneezing, nasal congestion, and runny nose. Many patients develop an irritating cough after several years of allergic rhinitis, where antibiotic cough suppressants are ineffective and even asthma symptoms such as chest tightness, breathlessness, and croup occur. The seasonality of pollen allergy is relatively clear, mostly occurring in spring and autumn. Patients with hay fever should go out as little as possible during the pollen dispersal season, especially to places where flowers and plants are concentrated, such as the countryside, and should keep doors and windows closed at home. If the diagnosis is clear, drug or desensitization treatment should be carried out under the guidance of a professional doctor. Dust mites are tiny organisms and are one of the important allergens in dust that cause allergic reactions. Dust mites are very vigorous and can grow and multiply very quickly in a warm and humid environment. Studies have found that dust mites are most abundant in mattresses, pillows, carpets, and fabric furniture. When the air is stirred (for example, when walking or vacuuming), dust mite allergen particles can float into the air; when the air is calm, these particles are deposited again. As with pollen, dust mite allergens are difficult to eliminate absolutely. Common insecticides and disinfectants are useless against dust mites and do not reduce dust mites and dust mite allergens. For patients allergic to dust mites, indoor furnishings should be simple and not too much furniture should be placed to facilitate cleaning; develop a “wet work” cleaning habit, do not use a broom to sweep the floor, do not use a duster to dust the furniture; try not to stack a lot of books in the bedroom; do not use carpets at home because they are prone to dust mites and mold; Air conditioners and heaters should be cleaned before use. In addition, dust mite allergy is best not to have pets, because the dander shed on pets is the food of dust mites. Molds live mainly in outdoor soil and reproduce by spores. Mold spores are very tiny, invisible to the naked eye, and are part of indoor dust, which is an airborne allergen. Mold spores can enter the room when the windows and doors are opened. The most common places for mold to grow in the home include damp corners such as kitchens and toilets. Poor ventilation in basements and first floors, indoor plants and flowers, garbage piles or fallen trees outside windows or doors have higher levels of indoor mold spores. For those who are allergic to mold, the damp corners of the room should be cleaned regularly, and if mold is found, it should be brushed off and rinsed dry in time, paying attention to keeping it dry. Should avoid keeping too many flowers and plants indoors. Food allergens Common food allergens include aquatic products, meat, eggs and milk, vegetables, fruits, nuts, etc. Many food allergies correlate with certain airborne allergens, such as spring pollen allergy, many of which are accompanied by fruit and vegetable allergies. Severe allergic reactions due to food allergens can be life-threatening. The best treatment for food allergies is to avoid eating the food after the allergen has been identified. It is recommended to read the food recipe list carefully before eating to know if there are any food ingredients that you are allergic to; when eating in restaurants, you should also ask carefully about the main ingredients and ingredients. It is worth noting that in China, many foods do not come with a clear list of ingredients, which can easily lead to unintentional intake by allergic people. The state should develop and implement mandatory regulations for expressing food formulas as soon as possible. Contact allergens include metals, fragrances, preservatives, hair dyes and certain topical medications. Allergic contact dermatitis is a common allergic skin disease that is easily overlooked and not easily cured if chronic. The best prevention is to identify and then not to be exposed to similar substances. Early diagnosis is very important. Failure to remove the allergen in time can lead to chronic inflammation of the skin.