Updated: Oct 11, 2021
TGIF dear friends! Even as the COVID continues to escalate in numbers, please do get yourself and your loved ones fully vaccinated! The evidence is very clear; if you are vaccinated, you are at a MUCH LOWER risk of serious infection / ICU admission and death.
Also, NCID advises us to continue mask wearing and observing SMM, as the Delta variant seems very infectious indeed!
Q: What is a dust mite allergy?
Dust mites are extremely tiny insects that belong to the spider family. They live in house dust and feed on the dead skin cells we humans regularly shed. Dust mites can survive in all climates and at most altitudes. They thrive best in warm environments, preferring those at 21°C and 70 percent relative humidity. Hence, Singapore is an ideal breeding ground for dust mites, especially with our urban, air-conditioned and carpeted homes and offices. Unlike in temperate climes, where seasonal allergy eg pollen is common, dust mite allergy is perennial or "year round".
When you breathe in the waste products of dust mites, your immune system kicks into high gear, producing antibodies against this normally harmless substance. This overzealous immune response causes the symptoms associated with a dust mite allergy, such as sneezing, itch, blocked and runny nose.
According to the Asthma and Allergy Foundation of America (AAFA), this type of allergy affects about 20 million people in the United States alone. Aside from allergy symptoms, long-term exposure to dust mite allergens may lead to sinus infections and asthma.
Image Illustrating a typical patient with Dust Mite Allergies, with nasal itch, sneezing and mucus
Q: What are the usual symptoms of dust mite allergy?
Dust mite allergy symptoms may range from mild to severe. They may include the following:
runny or itchy nose
post nasal drip
sinus pressure (may cause facial pain)
itchy, watery, or red eyes
swollen, bluish-colored skin beneath the eyes (eye bags or allergy shiners!)
trouble sleeping / disrupted sleep
You may experience additional symptoms if you have asthma and are allergic to dust mites. These symptoms may include:
chest pain or tightness
wheezing, coughing, or shortness of breath
severe asthma attack
Q: How do we diagnose dust mite allergies
You should see your GP, ENT Specialist or allergist if you find your symptoms are worse at home, especially when cleaning or when you go to bed. An allergist is someone who diagnoses and treats allergies.
Your allergist will use diagnostic tests to determine whether you have a dust mite allergy. The most common type of test is a skin-prick test. During this test, the allergist will prick an area of your skin with a small extract of the allergen. Your allergist will then wait about 15 to 20 minutes to see if your skin has any reactions. If you do have a reaction, you will likely develop a large bump (called the wheal) around the pricked area of skin. The area may also become red and itchy (called the flare).
A blood test is sometimes used instead of a skin test. Note that a blood test can only screen for antibodies, so the results may not be as accurate, as a provoked test like the skin prick test. However, the blood test can be useful for example, if you have eczema / urticaria or other skin conditions which may preclude accurate readings from doing the skin prick test. Do discuss this with your doctor.
Q: how can we prevent Dust mite allergies?
Bedding is the ideal breeding ground for dust mites. It’s usually the perfect temperature and humidity for them, and with us humans curled up at night provide the mites with an unlimited food supply.
Photo illustration of a House Dust Mite (under magnification)
Fortunately, it’s not a losing battle for those with dust mite allergies. You can take the following steps to help make sure your bed stays free of dust mites:
Use allergen-proof bed covers on the mattress, box spring, and pillows. Zippered covers are best. The tightly woven fabric prevents dust mites from getting into beds.
Wash all bedding in hot water at least once a week. This includes bed sheets, pillowcases, blankets, and bed covers. Dry in a hot dryer or in natural sunlight on sunny days.
There are more ways to manage dust mites. Unlike with outside allergens such as pollen, you can keep dust mites under control with a few key steps:
Use an air conditioner or dehumidifier to keep the relative humidity in your house between 30 and 50 percent.
Purchase a high-efficiency particulate air (HEPA) filter.
Buy only washable stuffed toys, and wash them often. Keep stuffed toys off the bed.
Dust frequently with either a damp or oiled towel or mop. This helps minimise the amount of dust and prevents it from accumulating.
Vacuum regularly using a vacuum cleaner with a HEPA filter. A person with a severe dust mite allergy should have someone else do this task.
Get rid of unnecessary clutter where dust tends to collect.
Clean curtains and upholstered furniture often.
Replace carpeting with wood, tile, linoleum, or vinyl flooring, if possible.
Q: How do we manage Dust Mite Allergies?
Well, there are several options available:
The best treatment option is to limit your exposure to dust mites. However, in our urban, air-conditioned and carpeted homes and offices, it is almost impossible to avoid dust mites. Apart from the environmental factors, there are several over-the-counter and prescription medications that can help relieve the symptoms of a dust mite allergy:
antihistamines, such as Telfast, Zyrtec or Clarityne, can help relieve sneezing, runny nose, and itching
nasal corticosteroids, such as Flixonase, Avamys or Nasonex, can reduce inflammation while offering fewer side effects than their oral counterparts
decongestants, such as Sudafed or Afrin, can shrink tissues in nasal passages, making it easier to breathe
medications that combine an antihistamine and decongestant, such as Actifed Zyrtec-D or Clarityne-D
Other treatments that may provide relief include:
Sublingual Immunotherapy (SLIT)
leukotriene modifiers such as Accolate, Zyflo, or Singulaire
Q: Is there a longer term cure for Dust Mite allergy?
Sublingual Immunotherapy (SLIT) is an alternative way to treat allergies without injections. Currently, the only forms of SLIT approved by the FDA are tablets for ragweed, northern pasture grasses like timothy hay and dust mites. In Singapore, our most common SLIT is done for Dust Mite Allergy (>90 percent).
The SLIT comes in 2 forms:
1. Sublingual drops eg DIATER SLIT
Laboratorios Diater has an effective form of administration of immunotherapy - the sublingual route. It consists of the administration of the allergen through the sublingual mucosa, by depositing the substance or allergen under the tongue and holding it there until completely absorbed.
The administration of this type of treatment, does not make it necessary to attend a medical centre or healthcare centre, since it may be administered daily in the patient’s home. In order to ensure the effectiveness of these treatments administered by this route, good patient compliance is of paramount importance, since administration is performed daily at home during the time estimated by the specialist.
According to the WHO, this can range from 3 to 5 years.
2. Dry dissolvable tablets eg ACARIZAX
ACARIZAX® contains an allergen extract from house dust mites. It comes in a tablet form which is intended to be absorbed in the body by placing it under the tongue.
ACARIZAX® is for the treatment of house dust mite allergy that is characterised by rhinitis (sneezing, runny or itchy nose, nasal congestion) in adults and adolescents aged 12 years and above. It is also for the treatment of house dust mite related allergic asthma in adults.
ACARIZAX® is currently not recommended for use in children below 12 years of age.
The tablets are placed under the tongue for one to two minutes and then swallowed as they dissolve. The process is repeated from three days a week to as often as daily. The tablets will increase your tolerance to the allergen eg dust mite and reduce your symptoms over time. For continued effectiveness, treatment may be needed for three years or longer.
If you are keen to seek treatment for your Dust Mite allergies, please do contact us today for a check up and more information. Till then, have a restful weekend, folks!
3. Banerjee S, Resch Y, Chen KW, Swoboda I, Focke-Tejkl M, Blatt K, Novak N, Wickman M, van Hage M, Ferrara R, Mari A, Purohit A, Pauli G, Sibanda EN, Ndlovu P, Thomas WR, Krzyzanek V, Tacke S, Malkus U, Valent P, Valenta R, Vrtala S. Der p 11 is a major allergen for house dust mite-allergic patients suffering from atopic dermatitis. J Invest Dermatol. 2015 Jan;135(1):102-109. [PMC free article] [PubMed]
4. Wan H, Winton HL, Soeller C, Tovey ER, Gruenert DC, Thompson PJ, Stewart GA, Taylor GW, Garrod DR, Cannell MB, Robinson C. Der p 1 facilitates transepithelial allergen delivery by disruption of tight junctions. J Clin Invest. 1999 Jul;104(1):123-33. [PMC free article] [PubMed]
5. Blythe ME, Williams JD, Smith JM. Distribution of pyroglyphid mites in Birmingham with particular reference to Euroglyphus maynei. Clin Allergy. 1974 Mar;4(1):25-33. [PubMed]
6. Thomas WR, Smith WA, Hales BJ. The allergenic specificities of the house dust mite. Chang Gung Med J. 2004 Aug;27(8):563-9. [PubMed]
7. Bousquet J, Dahl R, Khaltaev N. Global Alliance against Chronic Respiratory Diseases. Eur Respir J. 2007 Feb;29(2):233-9. [PubMed]
8. Weghofer M, Grote M, Resch Y, Casset A, Kneidinger M, Kopec J, Thomas WR, Fernández-Caldas E, Kabesch M, Ferrara R, Mari A, Purohit A, Pauli G, Horak F, Keller W, Valent P, Valenta R, Vrtala S. Identification of Der p 23, a peritrophin-like protein, as a new major Dermatophagoides pteronyssinus allergen associated with the peritrophic matrix of mite fecal pellets. J Immunol. 2013 Apr 01;190(7):3059-67. [PMC free article] [PubMed]
9. Sears MR, Herbison GP, Holdaway MD, Hewitt CJ, Flannery EM, Silva PA. The relative risks of sensitivity to grass pollen, house dust mite and cat dander in the development of childhood asthma. Clin Exp Allergy. 1989 Jul;19(4):419-24. [PubMed]
10. King C, Brennan S, Thompson PJ, Stewart GA. Dust mite proteolytic allergens induce cytokine release from cultured airway epithelium. J Immunol. 1998 Oct 01;161(7):3645-51. [PubMed]
12. Chapman MD, Wünschmann S, Pomés A. Proteases as Th2 adjuvants. Curr Allergy Asthma Rep. 2007 Sep;7(5):363-7. [PubMed]
13. Kalsheker NA, Deam S, Chambers L, Sreedharan S, Brocklehurst K, Lomas DA. The house dust mite allergen Der p1 catalytically inactivates alpha 1-antitrypsin by specific reactive centre loop cleavage: a mechanism that promotes airway inflammation and asthma. Biochem Biophys Res Commun. 1996 Apr 05;221(1):59-61. [PubMed]
14. Dust mite allergens and asthma--a worldwide problem. J Allergy Clin Immunol. 1989 Feb;83(2 Pt 1):416-27. [PubMed]
15. Custovic A, Taggart SC, Francis HC, Chapman MD, Woodcock A. Exposure to house dust mite allergens and the clinical activity of asthma. J Allergy Clin Immunol. 1996 Jul;98(1):64-72. [PubMed]
16. Custovic A, Chapman M. Risk levels for mite allergens. Are they meaningful? Allergy. 1998;53(48 Suppl):71-6. [PubMed]
17. Jang YH, Choi JK, Jin M, Choi YA, Ryoo ZY, Lee HS, Park PH, Kim SU, Kwon TK, Jang MH, Im SH, Moon SY, Lee WJ, Lee SJ, Kim DW, Kim SH. House Dust Mite Increases pro-Th2 Cytokines IL-25 and IL-33 via the Activation of TLR1/6 Signaling. J Invest Dermatol. 2017 Nov;137(11):2354-2361. [PubMed]
18. Turjanmaa K, Darsow U, Niggemann B, Rancé F, Vanto T, Werfel T. EAACI/GA2LEN position paper: present status of the atopy patch test. Allergy. 2006 Dec;61(12):1377-84. [PubMed]
19. Sturm GJ, Kranzelbinder B, Sturm EM, Heinemann A, Groselj-Strele A, Aberer W. The basophil activation test in the diagnosis of allergy: technical issues and critical factors. Allergy. 2009 Sep;64(9):1319-26. [PubMed]
20. Gosepath J, Amedee RG, Mann WJ. Nasal provocation testing as an international standard for evaluation of allergic and nonallergic rhinitis. Laryngoscope. 2005 Mar;115(3):512-6. [PubMed]
22. Kazemi-Shirazi L, Niederberger V, Linhart B, Lidholm J, Kraft D, Valenta R. Recombinant marker allergens: diagnostic gatekeepers for the treatment of allergy. Int Arch Allergy Immunol. 2002 Apr;127(4):259-68. [PubMed]
23. Jaén A, Sunyer J, Basagaña X, Chinn S, Zock JP, Antó JM, Burney P., European Community Respiratory Health Survey. Specific sensitization to common allergens and pulmonary function in the European Community Respiratory Health Survey. Clin Exp Allergy. 2002 Dec;32(12):1713-9. [PubMed]
25. Li CL, Lin HC, Lin CY, Hsu TF. Effectiveness of Hypertonic Saline Nasal Irrigation for Alleviating Allergic Rhinitis in Children: A Systematic Review and Meta-Analysis. J Clin Med. 2019 Jan 09;8(1) [PMC free article] [PubMed]
26. Nelson HS. New forms of allergy immunotherapy for rhinitis and asthma. Allergy Asthma Proc. 2014 Jul-Aug;35(4):271-7. [PubMed]
27. Eifan AO, Akkoc T, Yildiz A, Keles S, Ozdemir C, Bahceciler NN, Barlan IB. Clinical efficacy and immunological mechanisms of sublingual and subcutaneous immunotherapy in asthmatic/rhinitis children sensitized to house dust mite: an open randomized controlled trial. Clin Exp Allergy. 2010 Jun;40(6):922-32. [PubMed]