1. What an allergy is and what it provokes
The immune system of our body is able to recognize and fight certain substances which can cause harm to the body, such as viruses and bacteria; other substances that enter the body are harmless and for this are ignored. Allergens are harmless substances, but they can cause allergic reactions in some sensitivized people. Sensitivization: the immune system identifies the substance as an allergen. This phase takes place in a silent way after the first contact. The macrophages identify the substance that penetrated the organism and induce the reaction of T lymphocytes, which produce specific IgE against the allergen. IgE enter the bloodstream and adhere to the membrane of mast cells, defense cells located in the skin, lungs and nose. Mast cells will have the task of identifying the allergen when it comes into contact for the second time with the organism (immunological memory) .The allergic response itself, appears on the occasion of a subsequent contact with the allergen, resulting in demonstrations typical of allergies. IgE antibodies on the mast cell membrane recognize and capture the substance, causing the reaction of the immune system and the release of different active chemicals (histamine, leukotrienes, and other items). Prolonged exposure or adjust to the allergen can cause chronic inflammatory response and lead to disorders such as asthma, rhinitis, conjunctivitis and eczema (runny nose, sneezing, itching, swelling) .The reason why only some people develop allergies is not yet fully clear, perhaps this trend is a hereditary matter and/or determined by the contemporary lifestyle that promotes sensitivization (urban pollution).
2. Main allergens
The major allergens of our times are: pollen, mite feces, mold, certain foods, some animals' dandruff (dog and cat).
Among the allergens that may be encountered more frequently and that affects the majority of people, nearly 20 million only in Italy, is the dust mite: its feces! Mites are small organisms visible only under a microscope that feed mainly human and animal dander. Today's homes create a warm and humid microclimate, ideal for their proliferation (temperatures above 22 degrees and higher humidity of 60%) in particular mites lurk in mattresses, pillows, blankets, duvets, rugs, carpets and padded materials. The bedrooms are therefore the areas where the mites have the best condition to grow and multiply. If we consider that we all spend long hours in these rooms (children often longer than adults!) it is clear that drastically eliminating the mites from these environments is the most important strategy to defeat the allergies to dust mites.
The mite, or rather its allergens, are responsible for about 75% of respiratory allergies and can cause problems at any time during the year. The airways are in fact the favourite target mite's allergies, which can cause asthma, rhinitis, and, less frequently, conjunctivitis or eczema. Symptoms appear especially in winter, when, due to high temperature and high humidity, there are the ideal conditions for the growth of mites.
3. What are dust mites
Mites are animals belonging to the family of the tiny size of arachnids (between 200 and 400 thousandths of a millimeter) not visible to the human eye. They reproduce with extreme ease in favorable environmental conditions, with temperatures between 20 and 30 degrees with approximately 70% air humidity.
4. Where they live
Our homes are the ideal habitat for their development, even if clean and tidy. Dust mites feed on human and animal dandruff and flaking skin, they stay away from the light and seek refuge mainly in mattresses and pillows, where it is easier for them to feed, as they are in close contact with our body .Considering that we spend 1/3 of our lives bed, and that it is the "house dust mites", the exposure to a close contact is prolonged.