Dust mites and allergic diseases Dust mites are tiny arachnid arthropods hidden in modern living rooms, and their carcasses and excreta are the most common allergens that induce allergies. It is many allergic diseases such as hereditary atopic dermatitis (atopic dermatitis), chronic urticaria, allergic asthma, and allergic rhinitis are closely related to dust mites. If there are 100 dust mites per gram of room dust, it can cause atopic dermatitis patients with allergic qualities to be sensitized to dust mites, have positive serum dust mite specific IgE, and be in the incubation period; if the number of dust mites per gram of room dust exceeds 500, it has a higher risk of sensitization and is sufficient to induce rash and itching symptoms. Therefore, it is important to understand the habits of dust mites and reduce the number of dust mites in the room to prevent and alleviate allergic diseases. The dust mite is a tiny arthropod with 8 legs invisible to the naked eye, 170-500 microns long and 250-320 microns wide, and likes a warm and humid environment. The optimal growth environment is very similar to that of humans, with a temperature of 22-26 ℃ and humidity of 70-80%, living on dander (keratin) shed from the skin of humans or pet cats and dogs. Dust mites have seven periods: eggs, cocoon larvae, larvae, first larvae, second larvae, third larvae and adults. It takes about one month for the larvae to become adults, and the resting period from larvae to adults is prolonged when the ambient temperature and humidity are low, which reduces their survival rate. Dust mites can survive for about 2 months and the female mite lays 25 to 50 eggs at a time and can lay 200-300 eggs in her lifetime. Dust mites like to live in places where they can easily survive and multiply in mattresses, cloth sofas, long-haired clothes, fluffy toys, animal fur, carpets, Japanese tatami mats, old quilts, and vacuum cleaners that have not been cleaned in time, under suitable temperature and humidity. Their metabolites such as feces and proteins in their remains can cause allergic reactions in people with allergies if they are inhaled or come in contact with them. Ways to reduce dust mites, improve the health environment: regular cleaning of the home environment, with special attention to mattresses, cloth sofas, long-haired clothes, fluffy toys, animal fur, carpets, Japanese tatami mats, old cotton cleaning and disinfection and replacement. It is best to use wood and tile flooring, leather and wood products for sofas, and to use fine fiber bedding, such as the ultra-high density woven technology developed in Japan for dust mite resistant bedding, which can reduce the number of dust mites by 90% compared to ordinary bedding. It is best not to have pets such as cats and dogs if you have allergies in the family. Wear a mask and long-sleeved clothes when cleaning to prevent dust mite metabolites from dust inhalation or contact with skin. 1, physical prevention methods: dust mites are afraid of heat, 55 ℃ above 10 minutes can kill dust mites, 100 ℃ can make all the allergens associated with dust mites protein denaturation. Available hot water scalding, exposure to the sun, ironing and other methods can kill mites. Reducing room humidity can inhibit dust mite reproduction. When the relative humidity of the air is lower than 70%, the time for eggs to develop into adults can be extended by about 5 weeks, and when the relative humidity drops below 50%, it can lead to dehydration and death of adult mites. 2. Drug control methods: Commonly used acaricides include benzyl benzoate, Actomite, Tymasil, Nipah net, carbofuran, etc. When selecting acaricidal drugs, you must read the instructions carefully and master the concentration, dosage and use methods to prevent negative effects on human safety and health.