There are many kinds of mites which are the natural guests of our house, but the most important one from the point of allergic illnesses is house mite.
Their scientific name is dermatofagoides that means ‘skin eater’, because these creatures feed on human skin and hair eruption and dandruff. Mites belong to the same family with tick and spider; they are the natural guests of our houses, they do not carry any illness microbe. Although house mites have many kinds, the most frequently seen types are Dermatofagoides farinea and Dermatofagoides pteronyssinus.
1.5 gram of dandruff is erupted by an adult every day. This amount is enough for thousands of mites to feed for months. Mites are almost transparent and their length is about 1/3 millimeter. For this reason they cannot be easily seen with the naked eye, they can be seen with a magnifying glass or microscope.
CHARACTERISTICS OF MITES
They do not have eyes. They have eight legs. Their average life span is 3-4 months. A female mite lays 300 eggs. Mites best reproduce in environments where 20-25 °C temperature and %70-80 humidity are available. Very cold, little damp (dry air), bright and well aired places are not suitable for mites to reproduce. Mites rarely exist above 2000 meters height; they almost never live above 3000 meters height. For this reason, allergic illnesses related to mites are rarely seen on people who live in places higher than 2000 meters.
Modern life and its comforts accompany to their negations. Well isolated new buildings for energy saving, damp indoor air, wall-to-wall carpets are very suitable for mites to reproduce. Mites are most frequently exist on mattresses, carpets, bed quilts, cushions, armchairs, sofas, fur-skin, velvets, curtains, and downy toys. There aren’t many mites on surfaces of furniture; but there are millions of mites in an appropriate bed quilt.
It was shown that mites can exist on our dresses and even on our hair. It must also be known that there rarely might be mites in wheat flour and it might cause serious reactions like anaphylaxis on sensitive people. In order to determine mite levels in houses, there are prepared commercial tests that can be easily applied by everybody. One of them is Aclo Test, and the other is Acarex Test.
HOW DO MITES CAUSE ALLERGY?
Allergens related to mites are some enzymes that exist in digestion systems of these creatures and that are thrown with their excrements. One mite produces excrement 200 times heavier than its own weight during its life time. Mite excrement is in the shape of little spheres covered with mucus so they can easily stick on fibres of textile objects.
Allergens in mite excrement are in the structure of glycoprotein and they are resistant to heat and they dissolve in water. Excrement fragments containing these allergens become dry in time and decompose very small parts and they are thrown in to air during the movements like walking on the carpet, sitting on the armchair. It was shown that there might be more than 10.000 mites in 1 gram of house dust. It is accepted as a risk factor for allergic illnesses to occur if there are more than 2 micrograms of mite allergens in 1 gram of dust. It causes severe asthma attacks if there are more than 10 micrograms of allergen in 1 gram of dust.