Summer is here, when you sit in a cool air-conditioned room or air-conditioned car, you must be very happy! However, have you noticed that some people often suddenly “catch a cold”, a runny nose, sneezing, or coughing, breath-holding. After careful examination at the hospital, it turns out that they are allergic to dust mites. In fact, mites are a common organism, because of their small size, they can not be seen without a microscope, but they can be found in various natural conditions or human living environment. They can cause many allergic reactions in humans, such as allergic asthma, allergic rhinitis, atopic dermatitis and urticaria. With the modernization of people’s living and office environments, the incidence of allergic diseases related to dust mites is rapidly increasing. 1. What exactly are dust mites? Currently, in allergic (allergic) reactions, mites that can induce allergic reactions in humans in their living environment are the ones that should draw our attention the most. The main ones are dust mites and storage mites. Worldwide, the most dominant mites in the living room are dust mites (dust mites and house dust mites), and in tropical regions, tropical clawless mites are also the dominant allergenic mites. Dust mites are found on floors (especially carpets), mattresses, bedding (e.g., pillows), and sometimes soft furnishings and clothing; in addition, air conditioning filters tend to harbor and harbor dust mites. Mite bodies and mite excretions are the source of dust mite allergens. 2. Dust mites are closely related to allergic diseases Dust mites are one of the most important common inhalant allergens. Allergic reactions to dust mites can occur at all ages, and the incidence of their allergic reactions is increasing. Dust mites are the most important allergen in allergic rhinitis, with acute and delayed reactions to nasal irritation by dust mites, which, in addition, can play a further role in the development of nasal polyps by inducing inflammation of the nasal mucosa over time. The onset, development and persistence of symptoms of most allergic asthma are closely related to dust mite allergy. Dust mites are one of the most important allergens in atopic dermatitis, and the degree of allergy to dust mites in patients is closely related to the severity of atopic dermatitis. Dust mites can cause atopic dermatitis in two ways: (1) directly through the skin; (2) through inhalation of dust mite allergens; many patients with atopic dermatitis often have other allergic symptoms, such as asthma or allergic rhinitis. 3. Dust mites are difficult to eliminate, but can be controlled Since dust mites are difficult to completely eliminate, strictly speaking, it can only be said that dust mites can be controlled. Dust mite control methods have 3 goals: (1) reduce the total number of live mites; (2) reduce the level of mite allergens; (3) reduce human exposure to the first two. The method of achieving these 3 goals in a given room is influenced by many factors: most importantly, price, ease of implementation of the process, importance of the particular source of exposure, safety of the chemical used, and potential efficiency (benefit) of using the intervention method. When the number of mites in the room is extremely high and the patient has severe symptoms of allergic reactions, several methods are used simultaneously. The specific control methods and rationale are as follows: (1) Reduce the relative humidity in the room: controlling the relative humidity below 50% is the most commonly used method to control the level of mites and their allergens, since the surrounding relative humidity is the most critical factor influencing the prevalence of mites. Recent studies have shown that it is both practical and effective to use high performance dehumidifiers and air conditioners indoors to reduce the relative humidity and total number of mites. (2) Use of packing covers: Packing mattresses and pillows with special mite resistant materials is an effective way to reduce exposure to dust mites and their allergens. For allergy sufferers, this method is recommended. The packing material consists of plastic, breathable materials, very fine fabric fibers or non-fabric synthetic materials. The ideal material should be a comfortable, breathable fabric that is permeable to vapors and can block the passage of mites and mite allergens. The width of young mites is generally greater than 50 microns, so the fabric is less than or equal to 20 microns can stop all mites through. (3) Washing, drying and dry cleaning of bedding: sheets, pillowcases, blankets and mattress covers can be washed once a week with hot water equal to or higher than 55°C to kill mites and remove most mite allergens. Washing with lukewarm or cold water can remove most allergens. Washing with ordinary laundry detergent at 25°C and for at least 5 minutes will remove most mite allergens. Rolling dryers can kill all mites if the temperature is greater than 55°C and the time is maintained for 10 minutes. Dry cleaning is an effective way to kill mites, however, it does not remove all allergens. Washing your hair daily is also a good way to control dust mite allergens. (4) Carpet, curtain and home décor replacement: Carpet, curtain and home décor fabrics accumulate debris debris and remain damp, providing an ideal habitat for mites to breed. In humid areas, carpets should be replaced with hard surfaces. Window (cloth) curtains or blackout shades should be replaced with blinds, home décor fabrics should be replaced with vinyl or leather cushions, and furniture available in wood. (5) Carpet vacuuming: If the family is unwilling or financially not allowed to change the carpet, it should be vacuumed once a week and the vacuum cleaner bag should be replaced frequently. Vacuum cleaner bags should be double or high performance air filters or central vacuums with ends leading to the outdoors to avoid the formation of aerosols from allergens during vacuuming. Steam cleaning carpets may leave enough moisture in these areas to promote mite growth, which can backfire. (6) Freezing soft toys and small items: After freezing soft toys and small items (such as pillows and special clothing) at -17°C to -20°C for at least 24 hours, these items can be cleaned to remove dead mites and allergens. Leaving mattresses and pillows outside for 24 hours in colder zones is also a good method. (7) Chemical preparations: The key issue for indoor use of chemical preparations is the safety of the preparation, the form of efficiency products in the active ingredient in the preparation. The product must be able to deliver its active ingredient directly to the place where the mites live. (8) Dust mite control as part of the overall treatment of allergic diseases: Patients with perennial allergic rhinitis, asthma or atopic dermatitis who are allergic to mites and whose condition cannot be controlled by simple general or inhalation therapy should be recommended for mite allergen control. The recommended approach should be based on the extent of the patient’s disease, the climatic conditions where the patient lives, and the individual’s living environment. All patients should generally be advised to use coats for mattresses and pillows, change bedding that can be washed in hot water; and make adjustments to the bedroom to reduce space for mite growth and allergen accumulation. Controlling humidity as a medium to long-term goal needs to be discussed with the patient. In addition, if the patient is preparing to move, the patient should be advised to take a simple and effective control approach to mites and other allergens in the new home. In summary, dust mites are the most important source of indoor allergens in dust. Since dust mites are very closely related to allergic asthma, allergic rhinitis and atopic dermatitis, mite and mite allergen removal is essential, especially when moderate to severe symptoms are present. Beds, carpets, home furnishings and air conditioning are the 4 most important areas when it comes to mite removal.