Dust Mite Allergy

The dust mite
Dust mites are tiny microscopic mites that live in vast quantities within modern homes. Although virtually invisible to the human eye they live in close proximity to humans within their beds and in upholstered furniture, carpets and soft furnishings. Dust mites multiply very rapidly and it is believed that within 4-6 months a new mattress will be colonised. Dust mites do not bite and it is not the mite itself that causes problems but their faecal pellets, which contain an allergen known as DerP1. "The droppings are 4-20 microns in size, but they can crumble into fragments of 1-3 microns, and the tiniest bits are only 0.5 micros across." During their three month life span each dust mite lays 20-40 eggs and produces up to 2000 droppings. This causes the concentration of dust mite allergen to increase very rapidly. "Up to 1,000 individual mites can be counted in just one gram of dust (and there are approx. 28 grams in an ounce). This means that the average bed contains more than 10,000 dust mites and perhaps in excess of two million faecal pellets."

Where do dust mites live?
Dust mites thrive in the warm, humid conditions found in modern houses. They live in mattresses, bedding and carpets and any nice warm, dark, damp place where food is plentiful. "Dust mites live on shed skin scales from humans and animals, but only if the scales have been broken down by mould first. This is why humid conditions suit the dust mite so well. The other reason why mites need high humidity levels is that they do not drink, but absorb water from the air. When the relative humidity falls below 50 per cent, the mites gradually dry out and are killed." Therefore creating a dry atmosphere within the house will gradually make the environment intolerable for dust mites.
Dust mites are not more common in dirty houses and there is certainly no stigma connected to the presence of dust mites. In fact a relatively dusty house may be completely free of dust mites if the atmosphere is not conducive to their habitation; in other words, if it is not warm enough or moist enough for them to live. Dust mites are also destroyed by heat and sunlight so a well ventilated bed under a bright window may have low dust mite levels.

Symptoms of dust mite allergy
Dust mite allergy can develop at any age. "The most common symptoms resulting from house dust mite allergy are nasal symptoms, including sneezing, runny nose, rhinitis (hay fever), as well as sinusitis, with related headaches and ear blockages. Breathing symptoms, such as wheezing, dry persistent cough, tightness of breath and asthma, also commonly result. Eczema and dermatitis are frequently caused by house dust mites. Some people sensitive to dust mites report joint pain, swelling of tissues, and muscle aches." Dust mite allergy can also be a feature in almost any allergy. It is a known trigger for asthma and has also been connected to eczema. Generally anyone who suffers from dust mite allergy will feel worse when they come into contact with the allergen. This is particularly noticeable when they are in bed, when making beds or turning the mattress. Symptoms may also be exacerbated when sitting on sofas or armchairs, when in a carpeted house or office, when the heating comes on, after vacuuming with a vacuum cleaner that does not contain a HEPA filter or after any activity that is likely to churn up the dust mite allergen and release it into the air.

Reducing exposure to dust mite allergen
A multi-faceted approach is necessary to control the dust mite though measures will depend to a certain extent upon the severity of the allergy. For a milder allergy sometimes dust mite proof bedding is sufficient to see a significant improvement, whereas with more severe reactions measures should be taken throughout the whole house.

The bed
The most important place to start is with the bed as this is where we spend approximately one third of our time. Dust mite allergens can be released into the air every time we roll over or move the pillow. Although there are certain acaricides on the market that can be sprayed onto the mattress we strongly advise that you do not use these measures to combat mite population in the bedding. The active ingredients of insecticides of this kind are toxic and can off gas into the atmosphere while we sleep.

1. We recommend the use of dust mite proof barrier covers for the mattress, duvet and pillows, or alternatively choose a duvet and pillow that are in themselves dust mite proof. (Again if buying elsewhere you need to be careful that these have not been treated with insecticides.)
2. Use bedding that can be washed at 60 degrees as this will kill the dust mites and dissolve the water soluble allergens.
3. Use a steam cleaner to kill dust mites in existing bedding.

For further information and products please see the Dust Mite bedding section.

Flooring
Carpets can be a prime breading ground for dust mites. When vacuumed, walked on or disturbed in any way, the allergen can be released into the air and cause discomfort for the sufferer. This can be particularly bad for small children crawling or playing on the carpet. (We do not recommend that carpet treated with insecticide is used.)

1. Wherever possible and particularly if the allergy is severe, replace carpets with hard flooring. This should be damp mopped regularly. (We recommend the use of hard wood flooring or ceramic tiles, rather than vinyl, which can off gas toxins into the air.)
2. Vacuum carpets and floors regularly with an efficient vacuum cleaner. It is important that vacuum cleaners have HEPA s-class filtration to prevent allergens from being released back into the air.
3. Use a steam cleaner to kill dust mites in the carpet.

Upholstered furniture and curtains
1. Use a steam cleaner on upholstered furniture and curtains to kill the dust mites.
2. Blinds are recommended instead of curtains where there is a severe allergy.

Humidity control and ventilation
Humidity control is an important aspect of dust mite control. If the atmosphere is not moist enough for the mites they cannot survive. Ideally in order to reduce mite population the humidity level should be below 50%.
1. The ideal way to reduce extra humidity is to use a dehumidifier.
2. To check the humidity level in your house a weather station can be very useful.
3 Remove all sources of damp, rising damp and water leaks.
4 Ventilate the room well and open windows whenever possible. This will lower the humidity and help to clear out allergens.

Air
The faecal pellet of the dust mite is very light. Once disturbed, it is believed that they can stay in the air for at least 30 minutes. The dust mites themselves are relatively heavy and are not easily airborne.

1. Research shows that the Airfree air steriliser reduces dust mite population up to 80% as it combats directly the fungi that the dust mites need to suurvive.
2. Some people find that an efficient air purifier is helpful to clean the air in the room.

Disclaimer
Information included in this website is intended for information purposes only and is not to be used as a substitute for consultation with a medical practitioner.