Dust and Allergy

Dust is everywhere, all of the time. It is found indoors and outdoors, within households, workplaces, schools, cars and public places. Dust can be made up of virtually anything and everything. Dust can contain human skin cells, insect fragments and waste (e.g. dust mite or cockroach), animal dander, pollen, mould spores, food debris, paper or textile fibres, dirt, sand, minerals from outdoor soil, and countless other materials.

Every household has its own specific mix of dust. Dust is not dirt, nor is it an indication of poor housekeeping. Rather, it is a normal by-product of the breakdown of fibres and other substances found within a living environment. Dust accumulation is a natural process, thus the complete elimination and/or avoidance of dust is near impossible.

Exposure to dust can have adverse effects upon health. There are many substances embedded within dust that can trigger allergic reactions. Dust mites are the most common cause of allergy from dust. Other causes include cockroaches, mould, pollen and animal dander (ACAAI, 2014).

The absence of a diagnosed allergy does not however rule out the possibility an individual will experience untoward symptoms upon exposure to dust. This is because dust is an irritant in itself. Therefore regardless of whether or not someone has an identified allergy to a component within dust, the inhalation of dust particles can cause the nose, eyes, throat and respiratory passages to become temporarily irritated.

House dust mites and allergy

House dust mites are the most common cause of dust-related allergy. House dust mites are microscopic eight-legged creatures which are part of the arachnid family (relatives of spiders and ticks). They get their name from their habitat – household dust. Human living conditions are favourable to house dust mites because humans provide a source of both humidity and food. House dust mites thrive in warm, moist environments, and feed on the dead skin cells of humans (and their pets) found within dust.

Unlike most household bugs, house dust mites are relatively harmless. They do not bite, sting or burrow into skin, nor do they carry or transmit disease. Exposure to house dust mites is however a major source of allergy throughout the world. It is not the presence of the mites themselves which triggers allergy though. The house dust mite allergen is a protein which is contained within mite faecal matter and secretions (Stallergenes Australia Pty Ltd, 2013).

House dust mite allergy is the most commonly encountered dust-related allergy. It is the leading cause of perennial allergic rhinitis (persistent hayfever), and a primary trigger for asthma exacerbation, affecting up to 85% of asthmatics (Thomas et al., 2010). Contact with house dust mite allergens has also been associated with inflammation of the skin and worsening of atopic dermatitis (eczema) (Fuiano et al., 2010).

Living with a house dust mite allergy can be very unpleasant. House dust mites are present all year round and survive in all climates. They are found within most homes and are difficult to eliminate and avoid. House dust mite populations are usually highest within the bedroom – on mattresses, pillows and bed linen. Upholstered furniture, carpet, rugs, curtains and soft toys are other common places house dust mites densely inhabit (Lin & Nicholls, 2014).

The diagnosis and management of allergies is complicated, so individuals should always seek the assistance of a qualified medical professional. If an allergy to house dust mites is suspected, upon a doctor or allergist taking a detailed medical history, allergy testing may be ordered. This is usually in the form of a skin prick test or allergen-specific RAST (radioallergosorbent testing) allergy blood test (Lin and Nicholls, 2014). Alternative and unorthodox methods for allergy testing and treatment are not recommended, as they are neither evidence based nor scientifically proven as safe and effective.

Upon diagnosis, there are three main methods for managing a house dust mite allergy: allergen avoidance, pharmacotherapy and allergen-specific immunotherapy (Lin & Nicholls, 2014).

ALLERGEN AVOIDANCE

While there is no vacuum, dust mite spray or dry cleaning that will completely eliminate house dust mites, there are numerous techniques individuals can undertake in order to remove and minimise exposure to, the house dust mite allergen.

The first step is to maintain house dust mite popular areas. Bed linen, blankets, rugs, mats and soft toys should all be washed regularly (preferably weekly) at a minimum of 55 degrees Celsius. Eucalyptus based laundry detergents are recommended as eucalyptus not only removes the house dust mite allergen but kills up to 99.9% of the mites themselves (Felton Grimwade & Bosisto’s, 2014). Mattresses, upholstered furniture and carpets should also be vacuumed weekly. Vacuum cleaners with high-efficiency particulate air (HEPA) filters are most effective. If possible carpet, curtains, upholstered furniture and woollen-like underlays should be avoided, particularly within the bedroom (ASCIA, 2015).

Mattresses and bed linen are a reservoir for edible materials (human and pet skin cells) and a natural habitat for house dust mites. It is therefore not surprising house dust mite allergy sufferers commonly experience symptom exacerbation at bedtime and upon waking in the morning, report themselves to be mouth breathers and/or snorers, and complain of poor sleep quality. For individuals with severe symptoms, protective bedding can be purchased which is designed specifically to separate the allergy sufferer from the millions of house dust mite allergens that build up within mattresses, pillow cases and quilts/blankets (AllergEnd, 2015).

As previously mentioned, house dust mites thrive in warm, humid environments. To reduce house dust mite populations, it is therefore recommended houses (in particular bedrooms) are kept well ventilated and maintained at a moderate temperature of 18-20 degrees Celsius. The installation of a ventilation system or use a dehumidifier to reduce moisture, may be appropriate (Stallergenes Australia Pty Ltd, 2013).

For more information on ways to minimise exposure to house dust mites visit:
http://www.allergy.org.au/images/pcc/ASCIA_PCC_Allergen_minimisation_2015.pdf

For more information on eucalyptus based products for controlling house dust mites visit:
https://www.bosistos.com.au/blog/essential-oil/dust-mite-control-3-easy-and-natural-steps

For more information on house dust mite protective bedding visit:
http://www.allergend.com.au/page/how-to-control-and-manage-a-dust-mite-allergy/

PHARMACOTHERAPY

The elimination and avoidance of the house dust mite allergen is not always possible, or achievable to the extent individuals are effectively relieved of their allergic symptoms. There are however many pharmaceutical treatments available, both over-the-counter and by doctor’s prescription, which can help allergy sufferers gain symptom relief. Commonly used treatments include decongestant, antihistamine and steroid nasal sprays, oral antihistamines, and bronchodilator aerosol inhalers. It is important to note these treatments are designed to provide alleviation from symptoms only; they do not treat the cause. Seeking advice from a qualified medical professional or pharmacist prior to commencing pharmaceutical treatments, is always recommended (Lin and Nicholls, 2014).

ALLERGEN-SPECIFIC IMMUNOTHERAPY

Allergen-specific immunotherapy or “desensitisation” is the only treatment available which targets the cause of allergy (e.g. house dust mites) rather than just the symptoms. Immunotherapy “switches off” the allergy, by changing the way the immune system reacts to offending allergens. House dust mite allergen immunotherapy is often recommended for individuals suffering from severe allergic symptoms, to which allergen avoidance techniques are insufficient and pharmaceutical therapies are ineffective and/or inappropriate (ASCIA, 2014).

The benefits of house dust mite allergen immunotherapy are well documented. In a study by Liu et al. (2014), the relationship between house dust mite allergy, allergic rhinitis and asthma was investigated. Among patients with allergic asthma, management of house dust mite allergy with allergen-specific immunotherapy was demonstrated to effectively reduce asthma symptom severity, asthma medication use and allergen-specific airway hyper-responsiveness. Among patients suffering from allergic rhinitis without previous asthma symptoms, immunotherapy not only reduced their allergic symptoms, but the risk allergic rhinitis progressed into allergic asthma (Liu et al., 2014).

At the Australian Allergy Centre, we offer Medicare rebatable Skin Prick Testing for common aeroallergens such as house dust mite allergy treatment, and allergen specific immunotherapy for the treatment of allergic rhinitis and management of allergic asthma. For more information or to book an appointment, call us on 1300 MY ALLERGY.

Reference List:

AllergEnd. 2015. How to control and manage a dust mite allergy. Accessed August 25, 2015, http://www.allergend.com.au/page/how-to-control-and-manage-a-dust-mite-allergy/

American College of Allergy, Asthma and Immunology [ACAAI]. 2014. Dust Allergy. Accessed August 25, 2015, http://acaai.org/allergies/types/dust-allergy

Australasian Society of Clinical Immunology and Allergy [ASCIA]. 2015. Allergen minimisation: Information for patients, consumers and carers. Accessed August 30, 2015, http://www.allergy.org.au/images/pcc/ASCIA_PCC_Allergen_minimisation_2015.pdf

Australasian Society of Clinical Immunology and Allergy [ASCIA]. 2014. Immunotherapy for treatment of allergy. Accessed 7 August, 2015, http://www.allergy.org.au/patients/allergy-treatment/immunotherapy

Felton Grimwade & Bosisto’s. 2014. Dust mite control in 3 easy (and natural!) steps. Accessed August 25, 2015, https://www.bosistos.com.au/blog/essential-oil/dust-mite-control-3-easy-and-natural-steps

Fuiano, N., Fusilli, S. and Incorvaia, C. 2010. House dust mite-related allergic diseases: role of skin prick test, atopy patch test, and RAST in the diagnosis of different manifestations of allergy. European Journal of Pediatrics 169, 7, 819-824.

Lin, E. and Nicholls, K. 2014. A clinical approach to allergic rhinitis. Medicine Today 15, 10, 16-24. Accessed August 25, 2015, http://medicinetoday.com.au/sites/default/files/cpd/MT2014-10-016-LIN.pdf

Liu et al. 2014. House Dust Mite Allergy and Associated Allergen-Specific Immunotherapy in Allergic Asthma. Immunome Research 11, 1, 1-6.

Stallergenes Australia Pty Ltd. 2013. Allergic to dust mites? Author, Warriewood NSW.

Thomas, W., Hales, B. and Smith, W. 2010. House dust mite allergens in asthma and allergy. Trends in Molecular Medicine 16, 7, 321-328.