Harmony Women's Health
Dust Mite Allergy
Quietly lurking under our beds, inside sofas and carpet are creatures too small to see
without a microscope or strong magnifying glass. Dust mites are in the arachnid family which
includes spiders, scorpions, and ticks. Dust mites feed on dead skin that sloughs from our
bodies (and probably potato chips & cookie crumbs). They live their whole lives in dark corner
dust bunnies: hatching, growing, eating, defecating, mating, and laying eggs.
It's their bathroom habits that make us itch and wheeze. Many people develop severe
allergies to dust mite droppings. Lie on a rug where they live and you might get itchy red
bumps on your skin. Breath in dust and you may have more serious symptoms like difficulty
breathing or even a severe asthma attack.
What is house dust?
Rather than a single substance, so-called house dust is a varied mixture of potentially
allergenic materials. It may contain fibers from different types of fabrics; cotton lint, feathers,
and other stuffing materials; dander from cats, dogs, and other animals; bacteria; mold and
fungus spores (especially in damp areas); food particles; bits of plants and insects; and other
allergens peculiar to an individual home.
House dust also contains microscopic mites. These mites, which live in bedding,
upholstered furniture, and carpets, thrive in summer and die in winter. In a warm, humid
house, however, they continue to thrive even in the coldest months. The particles seen floating
in a shaft of sunlight include dead dust mites and their waste products. These waste products,
which are proteins, actually provoke the allergic reaction.
Waste products of cockroaches are also an important cause of allergy symptoms from
household allergens, particularly in some urban areas of the United States.
What are house dust mites?
Dust mites belong to the genus Dermatophagoides and are in the same Arachnid family
as the spider. They are so small they cannot be seen with the naked eye. They are oval shaped,
cream colored, eight legged creatures with sticky pads on the ends of their feet making it easy
for them to burrow deep in carpet fibers and furniture. Only the dead mite particles can be
They survive from eating human shed skin, fingernails, hair, pollen, fungi, bacteria, and
animal dander. They absorb moisture from the air and their environment. Their development
and food consumption increase if the humidity is between 70-80 percent and with temperatures
between 75-80 degrees. If the humidity is below 50 percent dust mites cannot survive.
They leave droppings everywhere they go. Their droppings contain leftover enzymes
which the mites use to digest the skin dust. It is these enzymes which are the most important
part of mite dust in causing asthma and other allergic diseases. In fact, house dust mites and
their droppings are the most important cause of asthma worldwide.
The cleanliness of the home or the presence of animals has nothing to do with the
number of mites in a home. Their population is determined by the humidity of the home, the
temperature of the home, and the amount of fabric or upholstery in the home. They do not
survive on vinyl or hardwood floors but are everywhere that dust accumulates.
The dust mite population increases very rapidly. Each egg-laying female can increase
the population by 25 to 30 mites every three weeks. Also each mite produces between 10 and
20 waste pellets each day. The life span of a mite is only two to three months, however.
modified from: Kettle, D.S. (1995). Medical and Veterinary Entomology. CAB International. Wallingford
At least 10 percent of the population suffers from dust mite allergy. Some of the symptoms
associated with it include sneezing, itchy, watery eyes, nasal stuffiness, runny nose, stuffy ears,
respiratory problems, atopic dermatitis, and asthma.
How can I tell whether house dust mites are causing allergies?
You can also tell to a fair extent for yourself, if there are enough clues in your case.
Here are some things to look out for:
If your allergies seem related to your work (gets better on holidays or at weekends), get
advice. The workplace may be making others around you sick and there are resources
available to address the issue.
If your allergy symptoms get better or worse according to your surroundings, it is likely
to be due to allergy, most often house dust mite allergy. Look out for:
o Allergies improving on vacations in hotels or drier climates.
o Allergies worsening in spare beds when staying at relatives or friends, or worse
in a car.
o Allergies worse when dusting the house, emptying the vacuum cleaner, or
Avoidance: Simple steps to relieving symptoms
It's not so simple. It's not enough to get rid of mites alone. To improve asthma or other
mite allergies you must get rid of the mites but also of nearly all the dust which they may have
left throughout your house over the years. This takes a huge effort. It is also very expensive
for most people. One reason for this is that mostly it is not enough to halve the amount of mite
material in your house. Worthwhile results mean cutting the house dust mite pollution to
BETWEEN ONE TENTH AND ONE HUNDREDTH of what it was before. But it can be
The key to reducing symptoms is the careful cleaning of all rooms where you spend
most of your time. Since we all spend about a third of our lives in the bedroom, that's the place
to start. Here are some simple steps you should take:
1. Since mites can grow abundantly in the dust in your bed, the single most important
thing you can do is to enclose mattresses, box springs, and pillows in vinyl or synthetic
2. Change bed linens every week and pillow cases every day.
3. Use washable blankets and bedspread. Wash bedding in hot water to kill the dust mite.
4. Eliminate upholstered furniture, carpeting, wall hangings, drapes, and other dust
collectors from the room.
5. Don't let items you rarely use gather dust in the closet. Don't store items under the bed
6. Dust collects in the nooks and crannies of textured wall and floor coverings. So, if
possible, use hardwood, vinyl or tile floors, and painted, paneled, or wallpapered walls.
7. Wet mop and vacuum frequently.
8. No stuffed toys. Toys should be made of plastic, wood, or metal.
9. Use air filtration devices to purify the air.
10. Maintain clean, adequate air filters for home heating and air conditioning systems to
avoid spreading allergens throughout the house.
11. Since the mite loves humidity, keep it as low as possible - 35% to 50% to retard its
proliferation by using dehumidifiers.
12. There are chemical agents for testing dust mites. Ask your doctor for details.
Another word of caution: do not make the treatment worse than the disease. A few
people get an obsession about cleaning the house and cripple themselves socially in an attempt
to avoid mites. This is a terrible result of well-meant advice. Do please rely on sound advice
from a recognised expert. The object of mite control should be a more normal life for the
member of your family with asthma or allergy and for the family.
Additional treatment for those with dust mite allergies
Symptoms of dust mite allergies can be improved with the regular use of antihistamines
and steroid-containing nasal sprays. Desensitization for dust mite allergies is somewhat
difficult because of the complex make-up of dust. Thus, an individual will need to be tested for
the dust mite, molds, pollens, etc to determine exactly what they are allergic to.
We're here to help.
If you believe you have a dust or other allergy, this office can help. We can perform a
number of simple, painless, and quick tests to determine exactly what may be causing the
allergic reaction. We can also provide an effective treatment plan and helpful hints to make
living with allergy a lot easier. Ask us for more information today.
The fundamental principles of mite control are:
Mite control will not work for you if you are not allergic to mites. Get the diagnosis
made properly before you spend a lot of money and effort. If your asthma does not
seem to be due to allergy, or is caused by allergy to something else than mites, act
If you are serious, be thorough. Dealing with one or two sources of mites is not likely
to help all that much. This may be OK if you just have mild nose allergy to mites, but
not if asthma is the problem.
Don't expect miracles. You will still be breathing mite dust from other sources.
Furthermore, the longer you have had asthma, the less good the result of mite control is
likely to be.
Deny the mites living space. Deny them access to the big open spaces of your bed,
and clean them off the surfaces. Remove the huge mass of carpet and cloth-covered
furniture in which you cannot attack them effectively.
Make your house climate unfriendly to mites. Don't allow humidity to build up, but
ventilate. Don't heat more or for longer than necessary.
Keep the mite dust out of your lungs. Avoid things which raise dust from reservoirs
such as furniture and the floor, where it is harmless, to the air you breathe. Cover
bedding with dust-proof material, avoid unnecessary dust-raising activity, avoid
breathing dust raised by vacuuming and cleaning, and avoid having the reservoirs such
as carpets and cloth-covered furniture from which airborne dust is raised. Wash or
clean clothing which is likely to be a reservoir. Avoid using vacuum cleaners where
damp dusting is possible. Use a good filtering vacuum cleaner where vacuum cleaning
Demand evidence before you spend money. Money you spend on things which don't
work is money you won't have for things which do work.