I. Reasons for the increase of allergic diseases in recent years and their main manifestations In recent years, there has been an increasing trend of allergic diseases worldwide, and it is agreed that they are mainly related to environmental factors, including the increasing environmental pollution, the increase of protein food, the long stay indoors and the decrease of exercise. Allergic reactions can be manifested as pruritic rashes (such as urticaria, contact dermatitis, etc.), redness of conjunctiva, nasal congestion, sneezing, watery mucus, asthma, etc. Second, the method of finding allergens and the significance of allergic diseases, the first thing is to look for allergens as much as possible. The methods to find allergens include medical history, skin test, blood test, patch test, etc. After finding the allergen, the most important measure is to avoid it. The improvement of the disease is rapid after avoiding allergens. Dust mites are arthropods that feed on the dander shed by people and often live in bed sheets, blankets and quilts, in addition, dead corners and carpets in the house can also become their residence. Foreign statistics show that more than 70% of households have dust mites. The most allergenic is the excrement of dust mites – fecal pellets. Dust mite allergy is a perennial problem that can be aggravated during the breeding season, as the number of dust mites at home is highest during April-May and September-October. Patients may present with hives, asthma, eye and nose infections, etc. Symptoms often worsen at night when lying down. How to remove dust mites? 1.Regularly improve indoor hygiene 2.Sweep the bed every night (avoid raising dust) 3.Expose bedding and carpets, etc. 4.Spray chemical agents for mite removal 4.Prevention of allergic diseases Allergic people (who had eczema as a child, have patients with allergic rhinitis or asthma at home) should pay attention to avoid allergens and irritants, the main surrounding environmental hygiene, no partial food, no animals.