What is a dust mite allergy?
House dust mite allergy is the most common of all the indoor allergens. It results from an inappropriate allergic reaction to house dust mites which are microscopic creatures, related to spiders, which can be found in moist warm environments such as soft furnishings.
How do dust mites cause allergies?
It is a common misconception that allergies are caused by dust particles themselves but instead allergies are directed very specifically at the faecal particles produced by house dust mites and not the mites themselves or other debris, for example, caused by having builders working in your home.
When do dust mite allergies develop?
Nobody is born with a dust mite allergy but these typically occur in later childhood or early adulthood. People who have a history of eczema especially in early life and also those with food allergies are more likely to develop dust mite allergies over time. Dust mite allergy in very common in asthma sufferers.
What are common dust mite allergy symptoms?
Classic dust mite allergy symptoms are similar to those of hay fever with nasal symptoms such as:
- runny nose and
- sneezing together with eye symptoms such as itchy, runny eyes.
The symptoms may be mild but for others they can be very significant affecting day to day activities especially in dusty environments.
How do you know if you have a dust mite allergy?
You may have noticed that you get symptoms when you are in dusty environments which you may be visiting and spending time in environments that are not regularly ventilated such as second homes. You may also notice symptoms when jumping up and down on settees or couches which tend to aerosolize a lot of dust mite particles. You might notice, for example, that when you go on holiday to a much drier or hotter climate that your symptoms get much better as house dust mites do not survive well at altitude or in temperature extremes.
How do you get tested for a dust mite allergy?
If you have symptoms that suggest a dust mite allergy, then this could be confirmed with:
Do dust mite allergies go away?
Typically, dust mite allergies run a protracted course lasting from childhood into adulthood although they do tend to improve, like other environmental allergies, as you reach old age. People with house dust mite allergy commonly have a history of eczema as well as other respiratory issues such as hay fever or asthma.
How can house dust mite allergy be treated?
Like any other allergy, avoidance is important although this can be difficult with house dust mite allergies. Certain measures such as occlusive covers for mattresses and pillows can be helpful and likewise it is important to vacuum regularly especially in the bedroom. Unfortunately, there is limited evidence that other measures to reduce dust mites are effective such as air filters or acaricides.
For those with more significant symptoms, it is also worth considering medication for house dust mite allergy treatment, this includes:
- long-acting non-sedating antihistamines
- nasal steroid sprays, when necessary and
- saline nasal sprays
- desensitisation (immunotherapy) is an important treatment option for those with severe symptoms.
What is house dust mite immunotherapy?
Some of the most exciting developments in the field of allergology are those in the field of desensitisation or immunotherapy, which has the potential to actually cure allergies by diverting the immune system’s response to a specific allergen such as dust mites.
In the past, this highly effective treatment was considered to be high risk because it involved regular injections that could potentially cause severe reactions. However, new forms of immunotherapy are now widely including immunotherapy for house dust mite allergy as well for allergy to pollen (hayfever), cat, dog and horse.
Who is suitable for dust mite desensitisation?
Patients who have a firm diagnosis of dust mite allergy together with symptoms that are not managed by regular medications such as antihistamines or steroid nasal sprays are usually the best candidates for house dust mite desensitisation.
Some people with less severe dust mite allergy who wish to minimise the use of steroid nasal sprays may also prefer this form of treatment.
Sublingual immunotherapy involves using a spray, tablet or drops made out of the problem allergen and it is then applied under the tongue on a daily basis rather than needing to use injections. Immunotherapy by the sublingual route is much safer (with over a million doses given globally) and thus can be given at home. As well as being shown to reduce the symptoms of dust mite allergy, there is now scientific evidence to suggest that desensitisation can reduce the risk of developing new allergies and also asthma.
Our team has a particular expertise in sublingual immunotherapy and a long track record of involvement in research as well as extensive clinical experience. Many of the treatments we use are only available in Specialist Allergy Centres.
Professor Adam Fox
Date reviewed: December 2021
Adam Fox is a Professor of Paediatric Allergy with over 20 years experience in both the NHS and private sector. Professor Fox is Commercial Medical Director at Guy’s & St Thomas’ Hospitals NHS Foundation Trust and Professor of Paediatric Allergy at King’s College London and the founding Director of the KCL Allergy Academy, a postgraduate educational programme, which was a finalist at the BMJ Awards in 2018.
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