What are dust mites?
Dust mites (dermatophagoides pteronyssinus and dermatophagoides farinae) are micro-organisms measuring 0.3 millimetres and thus invisible to the naked eye: their concentrations range from 10 to 1000 mites per gram of dust. The permanent habitat of these tiny arthropods - of different species the most common of which are the "dust mites" - is the home environment.
Dust mites are recognized as one of the sources of allergies.
Irritation of the skin, respiratory tract and eyes are generated by invisible contact with the digestive enzymes and droppings left by these microorganisms because they are rich in Der p 1 allergens. Likewise the glandular secretions they emit during moulting and the eggs deposited are a source of allergic sensitization in predisposed subjects. In our homes, the sites favoured by dust mites are mattresses, covers, curtains, carpets, pillows, furry toy animals and books left open to the air. The allergy-causing elements are the dust mite droppings which, when released in the air, are inhaled.
In mattresses, dust mites feed on small fragments of skin and dandruff normally shed during the night. Consequently, decreasing the dust mite concentration in the environment is the first and foremost step to reducing allergies. An extremely important environmental parameter for the development of dust mites is the relative humidity; in fact, if the relative humidity is below 60%, mites find development difficult. Generally, the greatest proliferation of dust mites is seen in spring and early winter and this is linked to the humidity factor.