Click here for a brief video about Dust Mites
Dust Mites
A
Closer Examination of the Dust Mite
The dust mite's mouth parts are grouped in front of the body, resembling
a head. Their body is oval and covered with fine striations. Their
eight tiny legs have small sticky pads which enable them to burrow
deep into carpet fibers and furniture, easily resisting the pull of
even the most powerful vacuum cleaners. You definitely would not want
to turn over in your bed and find yourself face to face with one of
these strange looking creatures. Unfortunately, that is where their
populations are often the highest. The average bed can easily have
over 10,000 dust mites living in it. Dust mites do not bite, sting
or transmit diseases, so they pose no harm except to people who are
allergic to a protein they produce. Their numbers have increased dramatically
in the past 20 to 30 years, especially during the winter months, partly
due to tighter homes where ventilation is limited and temperatures
tend to be warmer.
Egg-laying female mites can increase the population by 25 to 30 every
three weeks. They go through five stages in their life cycle; from
egg, the larvae stage, then two nymphal stages, and finally the adult.
The adult may also molt once. This cycle from egg to the adult takes
about one month. Adult mites can live up to two months, depending
on the humidity levels and temperatures of their environment. They
do not drink water but they absorb moisture from the air and their
environment. They just love higher relative humidities of 70-80% and
temperatures of 75-80 degrees F in which their development and food
consumption increases.
Dust Mites Produce a Powerful
Allergen
It is the protein DER p1 in the fecal products and disintegrating
body parts of these minute dust mites that has a mighty adverse effect
on those who are allergic to it. Dust mites produce about 20 pellets
per day, each measuring about 10 to 24 µm (micrometers - formerly
microns) in size. To put that in perspective, the diameter of the
human hair measures 80-100 µm. A gram of dust can hold 250,000
of these minute droppings. They are so tiny and light that they float
easily into the air when disturbed by our daily activities. Inhaling
these minute particles causes allergic reactions in those who are
sensitive to this protein.
Allergens from the dust mite which cause asthmatic symptoms was first
suggested in 1921 but analysis of dust did not happen until 1964 when
a group led by Voohorst suggested that a mite may be responsible for
the dust allergen. It was soon established that the dust mite droppings
contain an allergen so they became a focus over the years for their
involvement with respiratory ailments. The DER p1 produced by the
dust mite is though to be the most important allergen associated with
asthma. About 10% of the population are allergic to dust mite extracts.
Identifying the Sensitivity
to Dust Mite Protein
House dust contains many types of debris, including fabric fibers,
human skin scales, human and animal dander, bacteria, cockroach parts,
mold spores, food particles and other organic and synthetic materials.
About 90% of the people who are allergic to house dust extracts are
allergic to dust mite extracts. Symptoms which may come from sensitivities
to the dust mite protein include sneezing, congestion, itchy, watery
eyes and persistently stuffy nose and ears. Symptoms point more specifically
to dust mites when you experience repeated sneezing shortly after
awakening, symptoms get worse when beds are made or when using your
vacuum cleaner, and improve when you are outside. Diagnosis, using
scratch tests, etc., by an Allergist is recommended to determine which
allergens cause reactions. These doctors who specialize in treating
allergies can recommend a course of action specifically designed to
reduce or eliminate your allergic reactions. This may include steps
for reducing exposure to troublesome allergens, medical therapy and
desensitization injections (Systemic Immunotherapy - SIT). The latter
may be recommended if avoidance and medical therapy fail to sufficiently
reduce the allergic reaction. It involves injections of a dust mite
extract starting weekly, followed by injections every six weeks for
three to five years.
Importance of Reducing Exposure
to the Dust Mite Allergen
If your family is not sensitive to the dust mite protein DER p1, managing
them may not be a high priority. For those who suffer from it, management
by reducing exposure to the allergen DER p1 is quite important. Two
important aspects which need to be addressed are the removal of environments
which are conducive to dust and dust mites and the reduction of airborne
dust mite droppings and disintegrating body parts. Inhaling these
minute particles causes allergic reactions in those who are sensitive
to this protein.
The exposure level at which you experience allergic reactions is determined
by the sum of exposure to all allergens you're sensitive to. Those
who are sensitive to multiple allergens find that reduction of exposure
to any of the allergens will help in their tolerance of all the allergens.
It is important to realize that you do not need to completely eliminate
exposure to allergens. Simply keeping your total exposure of all allergens
below the threshold at which you experience reactions is all that
is necessary.
Reducing Exposure to Allergens
in Your Bed
Due to the amount of time we spend sleeping, our bedrooms are the
areas which deserve the most attention. Simply turning over in bed
or breathing near your pillow can cause you to inhale minute dust
mite droppings. Using hypo-allergenic fiberfill pillows is recommended
over feather, kapok or foam since they are more easily washed. Encasing
your pillows, mattress and box spring with plastic or specially coated
or finely woven (pore size < 10 µm) vapor- permeable fabrics
will deprive the dust mites of food and prevent many of the dust mite
droppings from reaching you. The fabrics are more comfortable since
they allow perspiration vapor to be more naturally carried away from
your skin. Thorough vacuuming the mattresses, especially the seams
and bed frame on a regular basis is also helpful. Wash your sheets
and mattress pads in soapy water at 130 degrees F every one or two
weeks to kill all mites. Bedding and curtains which can withstand
frequent washing should be selected. Blankets can be dry cleaned or
washed frequently. Using an electric blanket for eight hours every
day can reduce dust mites in beds significantly. Heating blankets
in a cloths dryer for several hours also kills mites. By doing this,
dry cleaning or washing of blankets can be reduced to once a year.
Wall to wall carpet and upholstered surfaces can be reduced or replaced
with hard surfaces that are easier to clean. Dust mites can not survive
long on hard surfaces due to dehydration. They absorb water through
contact with their environment. Dusting with a HEPA filtered vacuum
cleaner or specially treated cloths is recommended over damp mopping.
The latter may increase the humidity in the house. Dust mites can't
live at humidities below 50%. Using air conditioners and dehumidifiers
during the summer to keep the humidity between 40% and 50% is often
recommended. During winter, if using a humidifier, be careful to keep
the humidity in this same range. A good humidity gauge can help monitor
this. Carpets that get damp on a regular basis should be replaced
with hard surfaces.
Having carpets professional cleaned with superheated steam will effectively
killing dust mites in them. Carpets can be treated with sprays containing
3% tannic acid to make dust mite droppings non- allergic. Benzyl benzoate
powder which actually kills dust mites is also available. Reduction
of contact with dust mite droppings is often preferred since these
contain toxic chemicals which some people are sensitive to.
Reducing Exposure to Allergens
with Air Filters
Wearing a well fitting dust mask while vacuuming and making beds can
reduce the dust mite allergens you inhale. Some allergists even recommend
airing out a room really well after vacuuming to reduce the airborne
particles which are stirred up by many vacuum cleaners. Furnace mounted
and portable air cleaners are available but their cost may be greater
than the benefits achieved by them. They definitely are not a substitute
for the preventative measures described above. The best are media
type filters like those which meet the stringent HEPA specification.
Electrostatic filters are not recommended unless cleaned regularly
in which case they may be as effective. Special filters can be placed
on the furnace air vents leading to your rooms to help trap allergens
before they can enter the room. Air cleaners which generate ozone
should be avoided since they have little effect on allergens in the
air and may worsen allergy symptoms since the ozone may irritate the
respiratory system.
Importance of a HEPA Filtered
Vacuum Cleaner
The vacuum cleaner is one of the most important tools for managing
dust mites and their minute droppings. Thorough cleaning of carpets,
mattresses, upholstered furniture, curtains and drapery regularly
will reduce the dust mite allergens in your home. It is better to
clean thoroughly once a week instead of lightly every day. In order
to prevent these minute particles containing allergens from being
recirculated into the air you breathe, a vacuum cleaner's filtration
system must be very efficient at trapping particles at least that
small.
The agitation and air flow created by your vacuum cleaner to clean
you surfaces causes a huge number of minute dust mite dropping to
be drawn into it. They can easily pass through most vacuum cleaner
bags and filters and be exhausted back into the air you breathe, making
it much dirtier than before. The vacuum cleaner industry is taking
advantage of the development of advanced filtration media to provide
much higher quality exhausted air than was possible just a few years
ago. The current cutting edge in vacuum cleaner technology is in the
area of improving the filtration efficiencies of vacuum cleaners.
Special high filtration paper bags are available from many manufacturers
which filter much better than conventional ones. To learn more about
these high filtration paper bags, see ourarticle on the Dustbag Performance
and Filtration Efficiency.
To reduce the effects on allergies and asthma caused by the allergens
in dust mite droppings, look for a vacuum cleaner with a HEPA filter.
It also is very important to have a completely sealed system so all
air flow must pass through the HEPA filter to be cleaned by it. By
combining high filtration paper bags, a Certified HEPA filter and
completely sealed systems, vacuum cleaners can achieve extremely high
filtration efficiencies of 99.97% at 0.3 µm (micrometers - formerly
microns) size particles. For more information about HEPA filtration,
see our article titled "Filtration Efficiency - HEPA, ULPA, etc."
Summary
Dust mites are microscopic creatures which live at peace with all
of us, constantly going about their routine of cleaning up our environment.
Unfortunately, for about 10% of the population, the protein DER p1
in their minute droppings causes allergic reactions which affect their
respiratory systems causing allergic reactions and triggering asthmatic
attacks. A visit to an doctor specializing in allergies (allergist)
can confirm which allergens you are sensitive to. They are able to
prescribe a course of action which may include steps to reduce the
allergen exposure, medication therapy and possibly desensitization
injections.
Key steps to reduce exposure to dust mite allergens include encasing
mattresses and pillows, washing bedding and curtains regularly, controlling
humidity in you home and cleaning thoroughly with a powerful high
filtration vacuum cleaner. In extreme cases, carpets and upholstered
surfaces should be replaced with hard surfaces which are easier to
clean and which inhibit dust mite growth. The goal is to reduce allergen
exposure to below the level at which allergic reactions occur, not
necessarily the elimination of all exposure to the dust mite allergen.
The vacuum cleaner is one of the most important tools for managing
house dust mites and their minute droppings. Our site contains feature
articles describing a number of powerful vacuum cleaners which incorporate
very efficient Certified HEPA filters in completely sealed systems.
These include Models byMiele, Models by Lindhaus, Models by SEBO and
"True HEPA" Models by Eureka. Use of one of these is very
important in reducing airborne allergens during and after cleaning
your rooms. They can actually improve the quality of your indoor air,
making it smell fresher and feel cleaner.
Cleaning Alone is Not Enough
No Matter how spotless your home, it is impossible to eliminate or clean away dust mites. And most people can't bear to part with a beloved family pet even though this is the number one recommendation of doctors.
The secret of the ResponsibleCare System is the use of specialized cleaning agents followed by application of Allergy Relief Treatment on carpets, mattresses, upholstery, rugs, and bedding.
