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DUST MITES AND ALLERGIES
Dust mites are eight legged insects
that are part of the Arachnida class. There are an estimated 10
million types of mites. Out of those, there are over a dozen
species commonly found in houses. Hair follicle mites, scabies
mites, and house dust mites are the three types of mites that
are of particular interest to people. The typical size of a
dust mite is 420 ųm in length (almost 0.5 mm) and 250 to 320 ųm
in width. Dust mites cannot be seen with the naked eye. Both
male and female adult dust mites are globular in shape and
creamy white in color.
Dust mites do not bite however,
they feed primarily on human skin scales,
pollen, fungi, bacteria and animal dander. Mites have no
eyes but they find food because they live close to our bodies.
They are not capable of drinking water but they
absorb water from our skin and rooms that have high
relative humidity through glands in their legs.
The average life cycle for male dust
mites is 20-30 days. A pregnant female dust mite can live for
10 weeks. She will lay approximately 60 – 100 eggs in the last
five weeks of her life. In a 10-week life span, a dust mite
will produce approximately 2000 fecal particles and an even
larger number of partially digested enzyme-infested dust
particles.
Dust mites thrive in the environment
provided by beds, kitchens, and homes in general where the sun’s
rays do not reach them. Mites remain in mattresses, carpets,
furniture and bedding, since they can get lower into the fabric
in order to avoid sun, vacuum cleaners, and other hazards. They
can then climb higher, if necessary, to get more skin cells to
feed on. Dust mites in bedding derive moisture from human
breathing, perspiration, and saliva. On average a person sheds
enough flakes of skin cells in a year to feed roughly a million
dust mites under ideal conditions.
Dust mites eat miniscule particles
of organic matter. Some species of mites prefer to eat skin
cells, a large component of household dust; others prefer flour
dust. Dust mites have no stomach and require most digestion to
occur outside of their bodies. For this reason they secrete
enzymes and deposit the fungus Aspergillus repens on dust
particles, to enable the fungus to pre-digest the organic matter
with enzymes. Dust mites eat the same particle several times,
only partially digesting it each time. Between feedings dust
mites leave particles to decompose further. Ultimately a fully
digested particle is deemed by scientists to constitute fecal
matter.
The dust mite’s partially digested
food and the fecal pellet, sometimes called frass, are the most
significant sources of allergens. One of the more important
proteins responsible for the allergic reaction is DerP1, a
protease digestive enzyme found in mite feces. Frequent
vacuuming as a dust control measure may aggravate allergic
asthmatic conditions because conventional vacuum cleaners blow
some dust through the cleaner’s bag into the air. Vacuuming
helps remove the residue, as does washing, however; vacuuming
does not generally kill mites because they cling to the
surface. Prolonged exposure of skin to the proteins in dust
mite fecal matter reduces its barrier function; this weakness
can create a point of entry for allergens and irritants, leading
to inflammation and itchiness.
Dust mite allergen is relatively
heavy compared to other materials that contribute to dust
allergies, meaning it doesn’t float in the air as easily, and is
usually received close to the source; by inhaling near
mattresses, pillows, and stuffed toys.
About 10% of the population is
allergic to dust mites. This allergy is the primary cause of
perennial, or year-round, allergic rhinitis (irritation
and inflammation of some internal areas of the
nose).
Some symptoms from this allergy are, but not limited to:
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Runny nose
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Stuffy nose or ears
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Eczema
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Asthma
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Itchy, watery eyes
DID YOU KNOW:
A typical used mattress may have
anywhere from 100,000 to 10 million mites inside. Ten percent of
the weight of a two year old pillow can be composed of dead
mites and their droppings. (ref. Ohio State University)
For more information on how our professionally trained and
certified inspectors are able to come into your home and
potentially identify immediately if you have dust mites or
conditions that will increase dust mites contact us today at
800-773-2881.
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