One of the most highly
allergenic contaminants found indoors is house dust, often heavily contaminated with the
fecal pellets and skins of House Dust Mites. Estimates are that dust mites may be a
factor in 50 to 80 % of asthmatics, as well as in countless cases of eczema, hay fever,
and other allergic ailments. Common causes of allergy include house dust mites, cat
dander, cockroach droppings and grass pollen.
Symptoms
Are respiratory in nature, usually not a rash.
However, there are reports of a red rash around the neck. The wheeze-inducing
proteins are digestive juices from the mite gut and are potent. An exposure to the
mites in the first year of a infants life can trigger a lifelong allergy.
There
is no cure, only prevention.
One must control the levels of dust
mites. Beds are a prime habitat, a typical mattress may have anywhere from 100,000
to 10 million mites inside. Mites prefer warm, moist surroundings such as the inside
of a mattress when someone is on it. Their favorite food is dander (human skin
flakes), also, bedroom carpeting and household upholstery support high mite
populations.
Dust mites, due to their very small size
(250 to 300 microns in length) and translucent bodies, are not visible to the unaided
eye. For accurate identification, one needs at least 10X magnification.
Through a microscope, one will see many oval-shaped mites scuttling around and over one
another. There are eight hairy legs, no eyes, no antennae, a mouthpart group in
front of body (resembles a head) and a tough, translucent shell, giving a "fearsome
appearance".
Control
Measures
Recommendations focus on "dust
control". One must reduce the concentrations of dust borne allergens in the
living environment by controlling both allergen production and the dust which serves to
transport it.
