1. House dust mite Scientific classification Kingdom: Animalia
Phylum: Arthropoda Class: Arachnida Subclass: Acarina Order: Acariformes Family:
Pyroglyphidae Genus: Dermatophagoides Species: D. pteronyssinus Binomial name
Dermatophagoides pteronyssinus
(Trouessart, 1897)
The house dust mite (sometimes referred to by allergists as HDM) is a cosmopolitan guest in
human habitation. Dust mites feed on organic detritus such as flakes of shed human skin and
flourish in the stable environment of dwellings. House dust mites are a common cause of
asthma and allergic symptoms worldwide. The mite’s gut contains potent digestive enzymes
(notably proteases) that persist in their feces and are major inducers of allergic reactions such
as wheezing. The mite’s exoskeleton can also contribute to allergic reactions. The European
house dust mite (Dermatophagoides pteronyssinus) and the American house dust mite
(Dermatophagoides farinae) are two different species, but are not necessarily confined to
Europe or North America; a third species Euroglyphus maynei also occurs widely.
Contents
1 Description
2 Life cycle
3 Habitat and food
4 Asthma and allergies
5 Common beliefs and misconceptions
6 Eradication
7 See also
8 References
[edit] Description
9 External links
The body of a house dust mite is just visible against a dark background in normal light. A typical
house dust mite measures 0.4 millimetres (0.016 in) in length and 0.25–0.32 millimetre
(0.010–0.013 in) in width.[1] For accurate identification, one needs at least 10× magnification.
The body of the house dust mite has a striated cuticle. Like all acari, house dust mites have
eight legs (except the first instar, which has six).
[edit] Life cycle
1/8

2. The average life cycle for a male house dust mite is 10 to 19 days. A mated female house dust
mite can last up to 70 days, laying 60 to 100 eggs in the last 5 weeks of her life. In a 10-week
life span, a house dust mite will produce approximately 2,000 fecal particles and an even larger
number of partially digested enzyme-covered dust particles.[2]
[edit] Habitat and food
The house dust mite survives in all climates, even at high altitude. House dust mites thrive in the
indoor environment provided by homes, specifically in bedrooms and kitchens. Dust mites
survive well in mattresses, carpets, furniture and bedding, with figures around 100–500
animals/g dust.[3] Even in dry climates, house dust mites survive and reproduce easily in
bedding (especially in pillows), which takes up moisture from body contact.[4]
House dust mites consume minute particles of organic matter. Like all acari, house dust mites
have a simple gut; they have no stomach but rather diverticulae, which are sacs or pouches that
divert out of hollow organs. Like many decomposer animals, they select food that has been
already partially decomposed by fungi.
[edit] Asthma and allergies
Main articles: Asthma and Allergy
Allergens produced by house dust mites are among the most common triggers of asthma. There
are at least 15 mite allergens which are subdivided into groups. Group 1 and 2 allergens are the
most problematic. Group 1 consists of proteins with a catalytic activity, for example Der p 1
(Dermatophagoides pteronyssinus group 1) allergen is a cysteine protease, as is its American
counterpart Der f 1 (Dermatophagoides farinae group 1). Group 2 are proteins important for the
mite. Proteins from the other groups affect only few patients. Studies have shown the mean
attributable fraction of adult asthma due to atopic sensitization was 30% and 18% for
sensitization to dust mites.[5] Taken into consideration this could mean as many as 1.2 billion
people could have some form of chronic sensitization to dust mites.[5]
The allergy occurs because the immune system of allergy affected individuals, for reasons not
fully understood, misinterprets a usually innocuous substance as a disease agent and begins
producing a type of antibody against it, called immunoglobulin E (IgE).[6] This is called the
‘primary antibody response.’ The IgE produced during this response binds to basophils in the
bloodstream and to a similar type of cell called mast cells in the tissues. When the person again
encounters the allergen, these basophils and mast cells that have bound to IgE release
histamine, prostaglandins and leukotrienes, which causes inflammation of the surrounding
tissues, resulting in allergic symptoms. Most treatment has relied so far on trying to counteract
the released chemicals with anti-histamines, corticosteroids or Salbutamol. Commercial brands
of these medications most commonly prescribed to treat Asthma include Ventolin and Seretide.
Newer methods to try to treat house dust mite allergy involve immunotherapy. A safety and
tolerability clinical trial (Phase IIa) has been completed with positive results by Cytos
Biotechnology using an immunotherapeutic (CYT003-QbG10) for treatment of house dust
2/8

3. mite-triggered allergies.[7]
A 10 year controlled study in 60 mite sensitised, asthmatic children, showed almost complete
remission of asthma in those treated with sublingual immunotherapy (SLIT), and that this
remission was still apparent 5 years beyond the completion of treatment. [8]
This finding was supported by a review of 39 mite triggered asthmatic children, who were
suffering an average of 8 acute exacerbations per year. After treatment with SLIT, the
exacerbation rate was reduced by 95%. [9]
The French biopharmaceutical company Stallergenes is developing, via the Stalair Program,
sublingual desensitization treatments for house dust mite allergy. The immunotherapy tablet,
“Actair”, has demonstrated efficacy after 4 months of treatment and the persistence of its
therapeutic effect after only one year of treatment. (study VO57.07 conducted in Europe)
Stallergenes is now preparing filing NDA in Germany. A phase III pediatric study has been
launched.
Typical symptoms of house dust mite allergies are itchiness; sneezing; inflamed or infected
eczema skin; watering/reddening eye; sneezing repeatedly and frequently, e.g., on waking up or
sneezing 10 or more times; runny nose; and clogging in the lungs.
Dust mite immunotherapy is still not widespread, especially in countries such the UK. If allergic
asthmatic children cannot get access to desensitisation, then the best form of treatment for dust
mite allergies remains one of avoidance, although this requires a high level of commitment from
patient/parents. It is important however, to maintain use of medication such as anti-histamines,
corticosteroids or Salbutamol. The environment of bedding is optimal for most dust mites, and
comparative studies have shown that the density of dust mites in mattresses is on average
greater than 2500/gram of dust.[10] Cleaning beds with most vacuum cleaners will not remove
dust mite allergens, but instead throw them into the air and increase their volatility. Some
polyethylene bedding is beneficial as it makes the environment difficult for the dust mites. This
bedding should also be breathable and be able to withstand frequent washing. A home allergen
reduction plan has been recognized as being an essential part to the management of asthma
symptoms,[11] and therefore all aspects of the home environment should be considered (proper
vacuuming, use of air cleaners, etc.). The Asthma and Allergy Foundation of America as well as
the Asthma Society of Canada certify products that may be used in a home allergen reduction
plan in a Program called Asthma and Allergy Friendly.
[edit] Common beliefs and misconceptions
It is commonly believed that the accumulated detritus from dust mites can add significantly to
the weight of mattresses and pillows. While some recent studies have supported this claim,[12]
other reports dispute it.[13] However, more scientific evidence is needed for a complete
consensus.
Allergy and asthma sufferers are also often advised to avoid feather pillows due to the
presumed increased presence of the house dust mite allergen (Der p I). The reverse, however,
3/8

4. is true. A 1996 study from the British Medical Journal has shown that polyester fibre pillows
contained more than 8 times the total weight of Der p I and 3.57 times more micrograms of Der
p I per gram of fine dust than feather pillows.[14]
[edit] Eradication
House dust mites reproduce quickly enough that their effect on human health can be significant.
Since dust mites depend on moisture to survive, they are most often found in bedding such as
pillows and duvets.[1] Dust mites numbers can be reduced by replacing carpets with flat
surfaces that are easier to vacuum and maintaining relative humidity below 50%.[15] Existing
mites can be eradicated by regularly cleaning and washing items that harbour them, exposing
them to temperatures over 60 °C (140 °F) for a period of one hour or to temperatures below 0
°C (32 °F),[16][citation needed] through ten minutes’ exposure to the lethal temperatures –
near 105 °C (221 °F) – in a household clothes dryer,[17] or using disodium octaborate
tetrahydrate (DOT) powder.[18] A side-effect of DOT is irritation of eyes.
[edit] See also
[edit] References
List of mites associated with cutaneous reactions
^ a b Ella Davies (December 21, 2010). “Dust mites ‘swarm’ around houses”. BBC News.
http://news.bbc.co.uk/earth/hi/earth_news/newsid_9290000/9290068.stm. Retrieved September
11, 2012.
^ “Allergia agli acari” (in Italian). http://www.pneumologiamo.it/allergia_acari.htm.
^ “House Dust Allergy”. American College of Allergy, Asthma & Immunology.
http://www.acaai.org/allergist/allergies/Types/dust-allergy-information/Pages/default.aspx.
Retrieved September 12, 2012.
^ G. Daniel Brooks & Robert K. Bush (2009). “Allergens and other factors important in atopic
disease”. In Leslie Carroll Grammer & Paul A. Greenberger. Patterson’s Allergic Diseases (7th
ed.). Lippincott Williams & Wilkins. pp. 73–103. ISBN 978-0-7817-9425-1.
http://books.google.co.uk/books?id=H7GVhb27mo4C&pg=PA96.
^ a b Xavier Basagaña, Jordi Sunyer, Manolis Kogevinas, Jan-Paul Zock, Enric Duran-Tauleria,
Deborah Jarvis, Peter Burney, Josep Maria Anto, and on behalf of the European Community
Respiratory Health Survey (2004). “Socioeconomic Status and Asthma Prevalence in Young
Adults. The European Community Respiratory Health Survey”. American Journal of
Epidemiology 160 (2): 178–188. doi:10.1093/aje/kwh186. PMID 15234940.
^ J.-Y. Shim, B.-S. Kim, S.-H. Cho, K.-U. Min & S.-J. Hong (2003). “Allergen-specific
conventional immunotherapy decreases immunoglobulin E-mediated basophil histamine
releasability”. Clinical & Experimental Allergy 33 (1): 52–57.
doi:10.1046/j.1365-2222.2003.01567.x. PMID 12534549.
^ Staff (June 15, 2007). “Clinical Trials Update: Allergies”. Genetic Engineering &
Biotechnology News (Mary Ann Liebert, Inc.): p. 52.
^ Di Rienzo et al (2003). “Long-lasting effect of sublingual immunotherapy in children with
asthma due to house dust mite: a 10-year prospective study”. Clin Exp Allergy 33: 206-210.
^ Nuhoglu et al (2007). “Sublingual Immunotherapy to House Dust Mite in Pediatric Patients
With Allergic Rhinitis and Asthma: A Retrospective Analysis of Clinical Course Over a 3-Year
Follow-up Period”. J Investig Allergol Clin Immunol 17 (6): 375-378.
4/8

5. ^ Korsgaard, J; Iversen, M (1991). “Epidemiology of house dust mite allergy”. Allergy 46 Suppl
11: 14–8. doi:10.1111/j.1398-9995.1991.tb00643.x. PMID 1897695.
^ “Guidelines for the diagnosis and management of asthma.”. National Heart Lung and Blood
Institute. 2007. http://www.nhlbi.nih.gov/guidelines/asthma/.
^ MacRae, Fiona (June 22, 2011). “How your pillow is the perfect breeding ground for
gruesome array of pests and diseases”. Daily Mail. http://www.dailymail.co.uk/health/article-200
6760/Pillows-breeding-grounds-pests-diseases.html.
^ “Does a mattress double its weight due to dust mites and their debris?”. http://www.straightdo
pe.com/columns/read/2545/does-a-mattress-double-its-weight-due-to-dust-mites-and-their-debri
s.
^ T. J. Kemp, R. W. Siebers, D. Fishwick, G. B. O’Grady, P. Fitzharris & J. Crane (October 12
1996). “House dust mite allergen in pillows”. British Medical Journal 313 (7062): 916–919.
doi:10.1136/bmj.313.7062.916. PMC 2352227. PMID 8876094.
http://www.bmj.com/cgi/content/full/313/7062/916. “For many years asthmatic patients have
been told to avoid using feather filled pillows on their beds, although there is no evidence to
support this practice. Strachan and Carey’s case-control study is the first to have directly
challenged this assumption.1 This study showed that, after exclusion of asthmatic subjects
whose bedding had been changed because of their disease, pillows with synthetic fillings were
a risk factor for severe asthma. In the light of this finding, we have compared pillows with
synthetic and feather fillings for their content of Der p I, the major allergen of the house dust
mite Dermatophagoides pteronyssinus.”
^ Choi, SY; Lee, IY; Sohn, JH; Lee, YW; Shin, YS; Yong, TS; Hong, CS; Park, JW (2008).
“Optimal conditions for the removal of house dust mite, dog dander, and pollen allergens using
mechanical laundry”. Annals of allergy, asthma & immunology : official publication of the
American College of Allergy, Asthma, & Immunology 100 (6): 583–8.
doi:10.1016/S1081-1206(10)60060-9. PMID 18592823.
^ “Dust Mites, Do they do any good in the world?”. http://www.articlesbase.com/health-articles/
dust-mitesdo-they-do-any-good-in-the-world-1547581.html.
^ J. D. Miller, A. Miller (1996). “Ten minutes in a clothes dryer kills all mites in blankets”.
Journal of Allergy and Clinical Immunology 97 (1, part 3): 423.
doi:10.1016/S0091-6749(96)81180-8.
^ R. Codina, R. F. Lockey, R. Diwadkar, L. L. Mobly & S. Godfrey (2003). “Disodium octaborate
tetrahydrate (DOT) application and vacuum cleaning, a combined strategy to control house dust
mites”. Allergy 58 (4): 318–324. doi:10.1034/j.1398-9995.2003.00100.x. PMID 12708980.
[edit] External links
Arthropods portal
House Dust Mite site with research, animations and advice for patients and parents.
Dust Mite Information – Allergies, biology, control measures and locating dust mites
House dust mites on the University of Florida / Institute of Food and Agricultural Sciences
Featured Creatures website
v
t
e
5/8

6. Acari (ticks and mites)
Acariformes
Trombidiformes
Sphaerolichida
Prostigmata
Sarcoptiformes
Endeostigmata
Oribatida
Parasitiformes
Opilioacariformes
Opilioacaridae
Holothyrida
Allothyridae
Holothyridae
Neothyridae
Ixodida (ticks)
Argasidae
Ixodidae
Nuttalliellidae
6/8

7. Mesostigmata
Sejida
Sejoidea
Trigynaspida
Cercomegistoidea
Antennophoroidea
Celaenopsoidea
Fedrizzioidea
Megisthanoidea
Parantennuloidea
Aenictequoidea
Monogynaspida
Microgynioidea
Heatherelloidea
Thinozerconoidea
Polyaspidoidea
Uropodoidea
Trachyuropodoidea
Diarthrophalloidea
Epicrioidea
Zerconoidea
Arctacaroidea
Parasitoidea
Veigaioidea
Rhodacaroidea
Eviphidoidea
Ascoidea
Phytoseioidea
Dermanyssoidea
This article uses material from the Wikipedia article House Dust Mite, which is released under
the Creative Commons Attribution-Share-Alike License 3.0.
7/8

8. Check Out The Full Indepth Details Here: House Dust Mite
8/8
Powered by TCPDF (www.tcpdf.org)