It is the most important allergy in western countries, both for its widespread diffusion (modern homes create an ideal microclimate for the growth of mites at nearly all latitudes) and, above all, for the mite’s strong allergising power. It has been demonstrated that sensitisation to mites is the greatest risk factor for the development of asthma and that, by creating microscopic fissures in the mucosa of the respiratory apparatus, mite allergens favour the passage of other allergens, facilitating the onset of new allergies which aggravate the clinical picture. Despite these aspects, it is the easiest allergy to control with simple measures of environmental prophylaxis. It is easy to defend yourself against dust mites because their allergens are not scattered in the air, but build up in mattresses, pillows, blankets and duvets. Scientific studies have shown that, by covering these sites with certified anti-mite covers, it is possible to reduce the exposure to allergens from 100 to 1000 times in one month, with objective and appreciable benefits for allergic persons.
What are mites
Dust mites, or Dermatophagoides, are microorganisms similar to spiders and invisible to the naked eye, much smaller than one millimetre in diameter (they measure about 250 micron, a quarter of a mm). Although they are commonly called “dust mites”, they live almost exclusively in beds, where more than 94% of their allergens can be found. Only there do they find the conditions necessary for their survival:
1) Absence of sunlight:
light kills mites, that is why they nest in the internal layers of the mattress, the pillow and the duvet.
2) Temperature around 20°C and relative humidity between 60 and 80%,
conditions which are guaranteed by our body, which constantly loses humidity and warmth.
3) Plenty of food
As their name says, Dermatophagoides mites (skin eaters) feed on dandruff and flakes of skin which are continuously shed by our body (the skin detritus that we leave in the bed every night is enough to feed one thousand mites for a month).
What are mite allergens?
Mite allergens are the enzymes present in the mite’s excretions. They are relatively heavy, measuring from 10 to 30 micron, and they are not dispersed in the air, but remain deposited inside the mattresses, pillows and duvets where they are produced, accumulating in enormous quantities.
We come into contact with the allergens through our airways, because the weight and movements of the human body raise them just enough to let them reach our nose.
ADVICES TO REDUCE THE EXPOSURE TO DUST-MITE ALLERGENS
Bad habits, ineffective and expensive remedies
- Cleaning doesn't solve the problem. Continuously vacuuming, washing the floor, getting rid of rugs and carpets, heavy drapes and plush toys from the bedrooms of allergic children are excellent means of maintaining hygiene, but they do not solve the allergy problem. Dermatophagoides mites are not in house dust, which can be seen with the naked eye, deposited on floors, furniture or ornaments, because they are photophobic and die rapidly if exposed to sunlight. The only dust in which they may be found in large quantities is the dust that falls from the mattress, and that lies under the bed.
- It is no necessary to buy new mattresses or pillows frequently. It is of no use, because in just a few months they will be colonised by mites anyway. The important thing is to cover them with certified anti-mite encasings.
- Do not vacuum the mattress. This removes only the few mites that live on the surface and not the ones nesting in the internal layers.
- Do not use acaricide products on mattresses, pillows and couches. This eliminates only the few mites that live on the surface. Moreover, these products contain chemical substances that may have a toxic and irritating effect on the skin and mucosa, especially in the case of prolonged contact such as occurs in bed.