Centre for Allergy and Asthma Care (CAAC)
In order to reduce house dust mite allergens in the environment, we need to reduce the growth of the mites as well as remove the allergens themselves. As mite growth depends on humidity, reducing the relative humidity to below 50% for 5 days can kill the mites.
House dust mites
The droppings of house dust mites contain high levels of allergens. These allergens have enzymatic activities and will penetrate protective layers of the skin as well as mucous membrane. For people who are allergic to dust mites, exposure to these allergens will lead to allergic reaction. In fact, house dust mites are considered the most common allergens at home.
Allergy
Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur to normally harmless environmental substances known as allergens; these reactions are acquired, predictable, and rapid. Strictly, allergy is one of four forms of hypersensitivity and is called type I (or immediate) hypersensitivity. It is characterized by excessive activation of certain white blood cells called mast cells and basophils by a type of antibody known as IgE, resulting in an extreme inflammatory response.
Asthma and Allergy
Some main signs of allergy are itchiness, sneezing, inflamed or infected eczema, watering/reddening eyes, runny nose and clogging in the lungs. Allergens are tiny and light perfect for taking wing in the ducts and open air of spaces around your house. Allergens produced by house dust mites are among the most common triggers of asthma.
IgE and Asthma
Immunoglobulin E, or IgE, is a natural substance in your body that plays an important role in the development of allergic asthma. Increased levels of IgE may result when you are exposed to triggers, such as animal dander, dust mites and moulds. When you’re exposed to certain allergens, your body releases IgE, which then binds with several types of cells like basophils, lymphocytes & mast cells. This can then stimulate your immune system, cause your airways to become narrow and inflamed, and make your asthma symptoms worse.
Immediate Type Allergic Reactions
Type I (immediate type) allergic reactions are mediated by the IgE antibody. Low levels of immunoglobulin circulate in the blood stream as the majority is bound to the surface of mast cells and basophil granulocytes.
The binding of allergen epitopes to specific IgE antibodies, located on the surfaces of granulocytes, triggers the immediate release of pro-inflammatory mediators (histamine, enzyme, cytokines) which cause allergic symptoms.