Dust Mites: Everything You Might Not Want To Know!!!
By EHSO.com, the site for free, objective, practical information about the environment, health and safety in 2020!
Dust Mites: Everything You Might Not Want To Know!!!
Dust Mites: Everything You Might Not Want To Know! (Updated for October 2020)
Just thinking of these dust mites living in your pillow by the millions, eating your dead skin and hair is enough to make
you sick (literally and figuratively). The are a major cause of asthma and allergies;
especially in vulnerable individuals, such as children and the
According to the American College of
Asthma, Allergy & Immunology, approximately 10 percent of Americans
exhibit allergic sensitivity to dust mites. The American Lung
Associations tells us "Dust mites are not parasites; they don't bite,
sting or burrow into our bodies. The harmful allergen they create comes
from their fecal pellets and body fragments. Dust mites are nearly
everywhere; roughly four out of five homes in the United States have
detectable levels of dust mite allergen in at least one bed."
Don't you feel better now, know they don't bite or sting; and your
allergic reaction is only due to burying your face in a pillow full of
their feces? And you may feel better knowing, according to WebMD,
that "Dust mites like to eat dead skin from pets and humans. You
probably shed enough skin a day to feed a million dust mites."
In the spring,
pollen aggravates allergies, and dustmite infestations make it
worse. The Fall and
Winter months are a particular problem, as we close up our houses and
the concentrations of dust mites and their feces increases inside.
And with dustmites at their multiplying peak during warm, wet
weather, read on to find out what you can do about dust mites!
House dust mites are microscope bugs that primarily live on dead skin cells regularly shed from humans and their animal pets.
Dust mites are generally harmless to most people. They don't carry diseases, but
they can cause allergic reactions in asthmatics and others who are
allergic to their feces. People sometimes confuse dustmites with bed
bugs. See this page about bed
bugs and if you are going to a hotel or motel,
check this page
for tips specific to staying in hotels and motels.
Skin cells and scales, commonly called dander, are often concentrated in lounging areas, mattresses, frequently used furniture and associated carpeted areas,
often harbor large numbers of these microscopic mites. Since the
average human sloughs off 1/3 ounce (10 grams) of dead skin a week. That
gives dust mites a lot to eat. Cats and dogs create far more dander for
dust mites to eat.
A typical mattress can contain tens of thousands of dust mites. Sick yet? Nearly 100,000 mites can live in one square yard of carpet. Ready to convince your spouse to start bathing regularly? Did you know a single dust mite produces about 20 waste droppings each day, each containing a protein to which many people are allergic. Yuck! The proteins in that combination of feces and
shed skin are what cause allergic reactions in humans. Depending on the person and exposure, reactions can range from itchy eyes to asthma attacks. And finally, unlike other types of mites, house dust mites are not parasites, since they only eat dead tissue. Gross, but true.
Beds are a prime habitat (where 1/3 of life occurs). 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.) Mites prefer warm, moist surroundings such as the inside of a mattress when someone is on it. A favorite food is dander (both human and animal skin flakes). Humans shed about 1/5 ounce of dander (dead skin) each week. About 80 percent of the material seen floating in a sunbeam is actually skin flakes. Also, bedroom carpeting and household upholstery support high mite populations.
University of Manchester performed a 2005 medical study of pillows
that found up to 16 species of fungi in a single pillow. They tested
feather and synthetic pillows in a range of ages, finding thousands of
spores of fungus per gram of pillow ; more than is found on an average
And just when you thought they were confined to
your home and bedroom, there is a
news story in USA Today in which Jill Holdsworth is an infection
preventionist and president of the DC Metro Chapter of the Association
for Professionals in Infection Control and Epidemiology says the car can
be another place where dust mites live and a very big place to pass bacteria back and forth if you are not
careful, saying "The No. 1 hot spots would be anywhere that you touch
with your hands," Holdsworth said. These areas include the steering
wheel, radio, gear shift, cup holders and car seats."
For most people, while they are disgusting, house dust mites are not actually harmful. However, the medical significance of house dust mites arises because their microscopic cast skins and feces are a major constituent of house dust that induces allergic reactions in some individuals.
There is a genetic predisposition to dust mite allergies, but like many
allergies it can also develop over time.According to Darryl C. Zeldin,
acting director of the National Institute of Environmental Health
Services, in the Wall Street Journal (January 5, 2010, Page D2), 18% to
30% of Americans are allergic to dust mites' waste products, and almost
50% of American homes have allergen levels that are high enough to cause
sensitivity in people who were nt previously allergic to dustmites. In
other words, high levels of dust mites and their wastes, can cause
previously non-allergic people to develop an allergy. In addition to producing
allergic reactions, dust mites can also cause nasal polyps growths
within the nose (see
this article at 24 Medica). The constituents of house dust are show in the following figure:
Organisms in household dust:
ash, cigarette; ash, incinerator; combustion products; fiber, synthetic textile; fibers: wool, cotton, paper and silk; fingernail filings; food crumbs; glass particles; glue; graphite; hair, human and animal; insect fragments; oil soot; paint chips; plant parts; pollen; polymer foam particles; salt and sugar crystals; skin scales, humans; skin scales, pets; soil; spores, fungal; stone particles; tobacco; wood shavings *Drawn primarily from van Bronswijk, 1981.
For those individuals, inhaling the house dust allergen triggers
rhinitis allergica or bronchial asthma. People with allergies to house dust usually also have allergic reactions to
house dust mite fecal material and cast skins. Studies have shown that the most potent house dust allergens can be extracted from
the feces produced by dust mites. Other important allergen-producing organisms that are found in house dust are found in Figure 1.
The rest of this fact sheet, based on Chapter 10, "Mites," in Common-Sense Pest Control by Olkowski, Daar and
Olkowski, will discuss biology of dust mites and will emphasize non-chemical control tactics. An allergist, a medical doctor
specially trained to treat allergies, should be consulted for proper diagnosis and treatment of allergies.
One of the most strongly allergenic materials found indoors is house dust, often heavily contaminated with the fecal pellets and cast skins of House Dust Mites. Estimates are that dust mites may be a factor in 50 to 80 percent 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 usually respiratory in nature (sneezing, itching, watery eyes, wheezing, etc.), usually NOT A RASH. However, there are reports of a red rash around the neck. Other allergic reactions may include headaches, fatigue and depression.
The wheeze-inducing proteins are digestive juices from the mite gut which are quite potent. An exposure to the mites in the first, crucial year of life can trigger a lifelong allergy. There is no cure, only prevention. One must control house dust mite levels.
Beds are a prime habitat (where 1/3 of life occurs). 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.)
Mites prefer warm, moist surroundings such as the inside of a mattress when someone is on it. A favorite food is dander (both human and animal skin flakes). Humans shed about 1/5 ounce of dander (dead skin) each week. About 80 percent of the material seen floating in a sunbeam is actually skin flakes. Also, bedroom carpeting and household upholstery support high mite populations.
The protein substances in the dust mite feces
produces antibodies in humans who are allergic when these are
inhaled or touch the skin. These antibodies cause the release of
histamines which causes to nasal congestion, swelling and irritation
of the upper respiratory passages. The Mayo Clinic, WebMD and NIH
collectively provide this list of typical symptoms of an allergy to
dust mites; You may experience all or just some of them:
Asthma, difficulty in breathing,
Itchy, red or watery eyes
Itchy nose, roof of mouth or throat
Facial pressure and pain
Swollen, blue-colored skin under your eyes
In a child, frequent upward rubbing of the nose
A doctor can use skin tests and blood tests to
confirm a suspected dust mite allergy. In a
news story in the New York
Times (March 4, 2011) Dr. Diego Saporta, an otolaryngologist
in Elizabeth, N.J., who specializes in allergy management., says to ask: Do I have persistent sniffles and sinus headaches? Do I often wake up with
scratchy eyes? Do I sneeze repeatedly first thing in the morning? "Sometimes symptoms are obvious, but sometimes they are subtle," said Dr.
Saporta says. "Your only symptom might be chronic nasal
What else makes the symptoms worse?
High temperatures (above 70 F / 20 C)
Indoor air pollution such as tobacco smoke or
Walking over a rug, sitting down in a chair, or shakings the bed
clothes, makes the dried dust mite feces become airborne, making allergic person's symptoms worse.
House dust mites,
are too small to be visible to the naked eye; they are only 250 to 300 microns in length and
have translucent bodies. It takes at least a 10X magnification to be
able to correctly identify them. The adult mite's cuticle (covering) has simple striations that can be seen from both the dorsal (top) view and from the ventral (bottom) view. The ventral view of the house dust mite reveals long setae (hairs) extending from the outer margins of the body and shorter setae on the rest of the body. Through the 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 the body (resembles head) and a tough, translucent shell, giving a "fearsome appearance."
Adult females lay up to 40 to 80 eggs singly or in small groups of three to five. After eggs hatch, a six-legged larva emerges. After the first molt, an eight-legged nymph appears. After two nymphal stages occur, an eight-legged adult emerges. The life cycle from egg to adult is about one month with the adult living an additional one to three months.
The diet is varied with the primary food source, consisting of dander (skin scales) from humans and animals. However, needed nutrients can be provided from fish food flakes, pet food, fungi, cereals, crumbs, etc. Many mite species live in bird's nests, in barns, among stored grain, straw, etc.
House dust mites are cosmopolitan in distribution with much of the research previously done in Europe.
One of the major limiting factors in mite survival and population development is the availability of water for sorption. Highest mite densities occur in the humid summer months and lowest in drier winter periods. Dust mite populations are highest in humid regions and lowest in areas of high altitude and/or dry climates.
Due to the large quantity of skin scales sloughed off daily by humans, mites have an abundant food supply. Dust mite antigen levels are measured in bed dust, floor dust, and room air samples. Detection in room air was best during cleaning and bed-making activities.
House dust mite presence is often suspected before they are actually seen and accurately identified. Requests for control often come from individuals who have been diagnosed by medical personnel as allergic to the house dust mite or the allergens produced.
The presence of house dust mites can be confirmed microscopically which requires collecting samples from mattresses, couches or carpets. Also, it requires the use of a microscope with sufficient magnification and the technical ability to recognize house dust mites under the microscope. In general practice, testing is unnecessary. dustmites are extremely common in household environments. They virtually always show up in a test, so testing just adds expense. A better question than "are dust mites present?" is "How can I control or remove them?"
A number of researchers, like those
the University of Nebraska, have studied dust mite control and
have a set of recommendations that are proven to be effective. Recommendations focus on "dust control." One must reduce the concentration of dust borne allergens in the living environment by controlling both allergen production and the dust which serves to transport it. For the bedroom environment
you will want to use some or all of the following methods. We
have listed them in order of practicality combined with
The most effective means is to enclose
the mattress top and sides with a plastic cover or other
dust mite impervious cover (available here, click on allergy bedding on the left in the new page), thoroughly vacuuming mattress pillows and the base of the bed. Put an airtight plastic or polyurethane cover over your mattress.
This is the method recommended by Consumer Reports (see
their article here). This tip is number one for a reason: it is in your bed
(including the baby's crib) that you are closest to the mites and their feces and enclosing the mattress and pillows in a dust mite cover virtually eliminates the mites here.
like the dustmite-proof fitted sheets. Mattresses covered with "fitted sheets" help prevent the accumulation of human skin scales on the surface.
These sheets have the advantage of being waterproof, too, which
helps protect your mattress from spills, babies and toddler's
Reduce temperature and humidity: Dust mites love warm,
humid conditions, above 70 F (21 C) and 50% or greater humidity.
Temperature: Keep the thermostat in the house below 70 degrees. Humidity:
The National Institute of Health says an effective control of mites would require the maintenance of
relative humidity's below 50 percent. Here is a range of
dehumidifiers from a large basement or ground floor model, to a
small room model. The big ones are pricey, but they last
for many, many years. (we have one in the office that is 20
A study (Feb 2005) by Kingston University (London UK) shows that simply by leaving your bed unmade each morning, with the sheets to be exposed to the air, allows the sheets to dry out, and substantially reduces the numbers of dust mites.
Now, you have a legitimate reason not to make your bed!
Some researchers feel it is important to focus on decreasing indoor humidity, especially during the winter period to reduce dust mite populations. One might forsake humidifier use during winter periods
(or limit it to the bedroom only at night, then ventilate the
room during the day). It will help to use dehumidifiers during high-humidity periods, or use
central air conditioning. So if you use a humidifier in the winter, adjust it to produce 35% to 45% humidity. Some humidifiers have this control built in; with others, you'll need a humidity gauge (usually sold with a thermometer at
Costco, Sam's Club, Wal-Mart, Target, etc.). And generally, homes that have their air conditioners on constantly in the summer and dry heat in the winter have lower mite counts than non-air conditioned homes.
Wash your sheets,
pillows and blankets in very hot water. Wash the
sheets and blankets at least every two weeks. Wash your pillow every week
or put a dust mite-proof cover
(available here) on it and wash once per year. Your pillowcase goes over the
dust mite cover.How hot is hot? The water used to wash your sheets and blankets should be at least 130 F (54 C). Set your washing machine to it's hottest setting. If the water doesn't seem to be coming out hot, you may want to check your hot water heater - you may not realize that most household hot water heaters have a knob that can adjust the temperature of the water it produces. For fabrics that may not be washed in hot water; just pop it into the freezer for 24 to 48 hours to kill dust mites.
And for those who travel and stay in hotels (or with less hygienic friends and family): Take a
dust mite impervious cover (available here), along for when you stay at hotels - just think how disgusting their pillows must be!
Use Synthetic fabrics:
Replace feather and down pillows with those having synthetic fillings. Replace woolen blankets with nylon or cotton cellulose ones. And don't forget the children's stuffed animals: be sure to get washable stuffed animals in the future!
Memory foam mattress manufacturers claim that their mattresses
create an environment that is unfavorable to dust mites.
Even so, an encasement (dust
mite impervious cover) is still advised, also because it can
stop bedbugs (which
are a rapidly growing problem)
Clean weekly: Weekly change pillowcases, sheets, and under blankets, and vacuum the bed base and around the covered mattress. Clean flooring: Use a damp mop or rag to remove dust. Never use a dry cloth or broom, since this just stirs up mite allergens.
Clean daily: Daily damp dust the plastic mattress cover.
Frequently wash all bedding (blankets, mattress pads and comforters) in hot water (130 degrees F [or 60 C] weekly). Cold and warm water won't kill mites. Also wash curtains.
Steam clean surfaces and materials that cannot put put
through the washing machine: Using pure steam dissolves
dirt and grime, while removing germs and bacteria from the
surfaces that you're cleaning. Steam is also an economical and
environmentally friendly thing to do. There is no longer the
need to use harsh and toxic chemicals. It is also a great way to
kill dust mites and bed bugs. See this steam cleaner:
New Vapamore MR100 Primo Steam Cleaner.
install laminate flooring, wood, tile, linoleum, or vinyl floor covering. Remove cloth drapes and blinds. (If you have carpet, vacuum every day.) Vacuuming your carpets and upholstery every week can help.
See the caution about vacuuming below under tips. Vacuums with high-efficiency filters pick up more dust mites, but even standard vacuums work well enough.
Freezing and sunlight kills mites
but does not remove their residue. In addition to freezing temperatures and washing items in temperatures greater than 130 degrees F, extended exposure to sunlight, and low levels of humidity also destroy the mites.
Children's soft cloth toys: Regularly place soft toys in the freezer for 24 hours before you wash them, or wash them in hot water.
Removing them, or at least reducing the numbers of them on the
beds, will help, too.
Air Purifiers: While it is better to stop the dust mites
at the source, reducing the dust levels in the air is a good
secondary measure. Some pest control firms sell air purifiers to eliminate the food source of house dust mites. Although ozone air purifiers emit a low level of ozone (activated oxygen) that attaches to fungus, mold, and bacteria on skin flakes, EHSO does not recommend ozone generators (neither does the US Food and Drug Administration). The same ozone that is oxidizes the dust mites is bad for your health. Air purifiers that use HEPA
filtration are more effective and safe to use. Various types of air purifiers can be attached to the central air return to decrease irritants. Most filters remove 50 to 70 percent of material. HEPA filters will remove up to 99 percent of the material;
not just dust mite feces, but also all types of other allergens,
like animal dander, dust, pollen, cockroach feces, etc...
See this page for
information about selecting an air purifier.
Furnace Air Filters: Clean
or replace the air filters on your furnace or air conditioner at
least once a month. Filters that are rated to trap allergens are
obviously more effective than plain spun glass.
Services to Kill Dust Mites and Clean Mattresses?
There are companies offering a service, using steam or ultraviolet
light, to kill dust mites in mattresses and remove them. The Wall Street
Journal (January 5, 2010, Page D2) had an article by Laura Johnnes
titled "Does Mattress Cleaning Treat Dust-Mite Allergies?" Their
conclusion, including that of Dr. Peyton Eggleston, a pediatric
allergist and professor at Johns Hopkins Children's Hospital in
Baltimore, was that there isn't any scientific research or evidence to
back up the service companies claims, and that the dust mites would
probably return to previous levels within a month or two. This
substantiates the approaches above, including encasements (see number 1,
above). A cleaning might make sense if the mattress is fairly new
(1 to 3 years) and you encase it after the cleaning.
It should also be noted that people are rarely allergic
to only dust mites. When a person has an allergy to dust mites,
they are usually also allergic to other allergens. In
a report on WebMD (April 2008), Allergist Jonathan A. Bernstein, MD,
of the University of Cincinnati says, "You have to recognize that people
can be sensitive to multiple allergens -- as well as to non-allergic
triggers such as odorants, irritating chemicals, tobacco smoke, mildew,
and things of that nature, so these studies with just one or even two or
three interventions are fraught with limitations. Just to target dust
mites and then to say these interventions don't work is out of context
with patients' real lives."
In that WebMD article, which initially implies that dust mite
prevention methods are ineffective, the researchers insist that
"reducing allergens in the home and in the office will help patients
suffering from dust-mite allergy and asthma." They say reducing dust
mites is a good place to start. In other words, if you use methods that
reduce dust mite populations,
trap dust in HEPA filter air purifiers,
reduce humidity, which allows dustmites, molds, and other
allergens to flourish,
reduce surfaces that collect allergens (curtains, carpets,
This bottle ofdust mite laundry detergent is good for 64 washes.
No pesticides are currently labeled for house dust mites. However, two non-pesticide products, Acarosan and Allergy Control Solution are available for treatment of house dust mites and their allergens. The active ingredient of each is benzyl benzoate and tannic acid. Benzoic acid esters, such as benzyl benzoate, are very effective acaricides in both laboratory and field evaluations. Health risks appear to be slight as benzoates are rapidly metabolized in the body to hippuric acid, which is excreted in the urine. Most acaricidal studies for house dust mite control have been done in Europe. Before pesticide recommendations are made in the United States, approval will be needed by the Environmental Protection Agency (EPA). For additional information, telephone 1-800-7ASTHMA. ( 800-727-8462)
Keep temperature under 70 and humidity levels below 50 percent.
Dust mites as well as other allergens thrive on high humidity. Homes with air conditioning constantly have lower mite counts then non-air conditioned homes. This can be accomplished with a couple of relatively inexpensive and long-lasting dehumidifiers. These have the advantage of making the air more comfortable in the summer, reducing the need for air conditioning.
Wash bedding, rugs, children's soft toys and pet's bedding frequently
"Frequently" means at least every two weeks in very hot water.
Don't be like these Brits: according to a
news story in the Daily Mail, a poll suggests that "more than
half a million Britons only wash their sheets three times a year,
allowing some 10 million bugs and dust mites to settle in for a
night cap alongside them."
Keep the house clean Dust mites,
pollens, animal dander, and the allergy causing agents can
be reduced, although not eliminated through regular cleaning.
Use a good HEPA vacuum.
Most non-HEPA vacuums actually cause the problem to worsen because the filter bags in most models are not efficient and cause allergen levels to rise.
A good HEPA vacuum, like the Hoover Wind Tunnel series will pick up
at least some dust mites and their eggs and trap all it picks up.
Some vacuums are now being designed to kill dust mites. Halo
Technologies says its uprights, including the $400 UVX, kill dust
mites, flea eggs, and germs using UV light. Consumer Reports hasn't
yet tested those claims because this model wasn't very good at the
basic tasks of cleaning carpets and picking up pet hair. Watch here
for future developments.
Use a good air filter to remove airborne allergans
- Most store bought air filters an not capable of trapping mites and their by-products.
One should also look for a filter that has anti-microbial properties, to prevent the filter from becoming a breeding ground for allergens.
Filters that call themselves "washable" should be avoided because it just is not possible to wash 100% of the biological
contaminants out of them and they will also become a breeding ground. The Honeywell brand with inexpensive replaceable prefilters and
long-lasting HEPA filters work well for us.
October 29, 2016 - Allergic and
non-allergic dust mite proteins - An NIEHS study provided new information about the characteristics of dust mite proteins
that may help researchers understand the development of dust mite allergy and assist in the design of better allergy therapies.
March 8, 2011 - CBS News -
Allergy-proof your home to sniffle less - A little preparation for
upcoming spring allergy season could help you cut down on your
suffering. "/...if you're one of the 20 million people who are
allergic to them, make sure you take steps to clean. You'll want to
eliminate dust mites and the dead skin cells they eat by washing
bedding in hot water at least once a week. Turn up the water heater
to a dust mite-killing 130 degrees before you wash, and turn it back
down afterward. Another good option is using an anti-allergy
mattress wrap, which can keep mite waste from contaminating your
air. You'll also want to keep an eye on the pillows -- two years is
the magic number when it comes to pillows. To reduce the onset of a
major allergy attack and prolong the life of your pillows, have them
dry-cleaned or wash them in boiling water."
December 21, 2010 - BBC, "Earth News" Section -
Dust mites "swarm" around houses, migrating as a group in search of
moisture, according to a new study. The collective
movement happens when mites leave a dry area in search of higher
humidity - the greatest source of which in a house is its human
occupants. Mites gain nutrients from dead skin but also depend on
moist air for survival. "We expected the mites to move to areas of
higher humidity, because they are dependent on air moisture to
survive," said co-author Anne-Catherine Mailleux. "However, the fact
that they attract each other and prefer to move together rather than
independently from one another was an important finding."
Researchers knew that house dust mites were unable to drink and
depended on moisture in the air to survive.
March 3, 2008: Dust mites and cockroach feces and other gens
may make it harder for
skin to heal, news reports say South Korean researchers
report. Reported in
Reuters, the Journal of Investigative Dermatology, researchers
said it was important, especially for people with eczema, to protect
themselves from such microscopic bugs and filth. Dust mite and
cockroach allergens are particles of feces, saliva and other matter
found on the bodies of these insects.
February 1, 2008: Dust Mite Resistant Car Seat Covers -
reports that Toyota has announced the development of the worldâ€™s
first car seat fabric agent that stops 98% of dust mites from
becoming active. Toyota intends to begin offering this new treatment
on vehicles sold in Japan in the next few years.
feeling queasy? Well, follow the links below for more information, but not near dinner (or bed) time!
Pollen Calendar A very useful website to tell you what is blooming when in your area! Works anywhere in the world.
The Wall Street Journal, Tuesday, October 13, 2009,
has an interesting article on page D5, titled, "Sneeze Sleuths:
Uncovering Allergies' Secrets". f you have an online
subscription, you can read it there. They interviewed a couple of
researchers in Charlottesville, Virginia (it is not clear whether
they are affiliated with the University of Virginia or not), named
Dr. Anna Pomes and Dr. Martin Chapman. The researchers are
investigating the mechanisms of allergic reaction.
DustMites Clemson University's fact sheet on controlling dust mites, which are second only to pollen in causing allergic reactions
Dust Mite Research The Ohio State University Acarine Physiology Laboratoryâ€™s research agenda consists of basic and applied research on ticks and mites of medical importance. Our current mite research focuses on novel methods for controlling house mites.