I. Dust mites and asthma 1. Epidemiological studies have shown that dust mites are a risk factor for the development of asthma in children and adults. In the vast majority of the world, the most important and persistent risk factor in the development of asthma for both children and adults is dust mite allergy. The development of dust mite induced allergic asthma is interrelated with genetic predisposition, environmental triggers and allergen exposure: patients develop allergy under the combined effect of three factors: environmental triggers, genetic predisposition and exposure to allergens, and asthma symptoms can occur if re-exposed to allergic principles. 2. In patients allergic to dust mites, the severity of asthma symptoms correlates with the level degree of exposure. 3. In children and adults allergic to dust mites, significant reversal of asthma occurs after non-exposure to dust mites, symptoms and lung function improve, and airway inflammation and hyperresponsiveness are reduced. 4. Control of dust mite allergens has a significant effect in asthma prevention and treatment. Dust mite allergy and allergic rhinitis Studies have shown that dust mite is the most important allergen for allergic rhinitis. As one of the most important allergens in allergic rhinitis, dust mites can play a role in the development of nasal polyps by inducing inflammation of the nasal mucosa over a long period of time. Third, dust mites and atopic dermatitis The prevalence of atopic dermatitis (also known as atopic dermatitis) in children is 10%, and dust mites are one of the most important allergens in atopic dermatitis. The degree of allergy to dust mites 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 that can also cause atopic dermatitis. Many patients with atopic dermatitis often have other allergic symptoms, such as asthma or allergic rhinitis. Fourth, dust mite allergy and multiple allergies 1. dust mite allergy and food allergy: cross-reactivity of dust mite allergens and other invertebrate allergens can lead to or aggravate food allergy (e.g., shrimp, snails). 2. Dust mite allergy and other allergies: cross-reactivity of dust mite allergens and other invertebrate allergens can lead to or aggravate food allergy, in addition to inhalation allergy (other mites and cockroaches), allergy to shaking mosquitoes and local skin reactions.