Recently I’ve been waking up feeling a bit like I’m about to get a cold. At night my nose got stuffy and irritated, in the morning I’d have itchy, puffy eyes, and thick head. However as the day went on, my eyes got better and my nose and head felt normal. Only to happen all over again the next night.
I’ve always been a little prone to allergies, itchy eyes from pollen, and puffy eyes from dust mites. I suspected that the house dust mites had built up in our bedroom. I’d been a bit lazy lately, the bedroom carpet hadn’t been thoroughly vacuumed for a while, and dust had built up under the bed.
Dust mites are a big problem in New Zealand especially with our warm humid houses. It is the major cause of allergy in persons with year-round complaints of stuffy nose, sneezing and watery eyes — what some people describe as a “permanent cold”. In addition to these allergic reactions, dust mite can trigger asthma and eczema.
Of those who develop asthma in the first 10 years of life, over 75% will show a positive skin prick test to house dust mite. When challenged by inhaling dust mite, a similar percentage will show an immediate asthma response. (Auckland Allergy Clinic)
House dust mites live on human skin scales and other debris. They have a very precarious water balance. They absorb water through their leg joints from the environment. They have no mechanism of searching for or drinking liquids and are thus entirely dependent on ambient humidity. They survive and multiply best when the relative humidity is at 75-80%.(Auckland has this humidity or higher all year round) It is not surprising we have such a big house dust mite problem.
So if you have been waking up feeling like you are getting a cold, or you are prone to asthma or eczema, it may pay to do a dust mite blitz in your house.
I’ve vacuumed using a vacuum cleaner with a HEPA filter. Stripped my bed and vacuumed the mattress, electric blanket and pillows. Washed all the bedding – dust mites can build up in duvet, mattress protectors, pillows and blankets. It was worth the effort, last night I slept with a clear nose, and woke with a clear head and eyes.
You may need to be more ruthless depending on your level of sensitivity. For example getting immunotherapy treatment.
You may also need to clean more ruthlessly, for example regularly steam clean the mattresses, and launder curtains. Or even remove the carpet in your bedroom so the little creatures don’t have a nice warm damp home, but a vinyl or wood floor instead. Covering your mattress and pillow with dust mite covers will stop them and their feces floating round your face at night.
Family Doctor website has a good list of tips to get rid of dust mite
Raised ambient temperature, ultra-violet light and a relative humidity of less than 55% are all lethal to house dust mites.
These can be achieved as follows:
- Wash bedding, pillows, duvet and mattress covers in HOT water of greater than 55 degrees Centigrade.
- Expose the mattress to the sun’s UV light for a few hours each month.
- Turn an electric blanket on to HIGH for a few hours each month. Many mites will be killed near the mattress surface.
- Where available, use an air conditioner or dehumidifier to maintain bedroom humidity below 50%.
- Chemical agents which kill mites are available in New Zealand, but these have not been found to be very effective.
Remove Mites & Mite Protein
Even if mites are dead, their bodies and excreta can still cause allergic reactions. Removal can be achieved as follows:
- Intensive vacuuming of mattress, carpets and furniture is needed once a week. The more vigorous and effective the cleaner the better. It is vitally important that house-dust mite and other allergenic particles once sucked up into the vacuum cleaner are prevented from leaving the cleaner through its exhaust opening. The most effective way of controlling this efflux is undoubtedly the HEPA (High Efficiency Particulate Air) filter. HEPA filters retain 99.9% of particles in the range of 0.3 to 0.5 micrometers and will retain housedust mite, cat and mould allergens. Vacuum cleaners which incorporate both a double dust bag and HEPA filters are the best choice for allergy sufferers.
- Weekly hot water washing (55 degrees Centigrade) will kill mites and remove bodies and excreta. Curtains should be laundered at regular intervals.
- House dust mites and their excreta accumulate on dusty surfaces, in drawers and on clothes. Using a damp cloth, dust all exposed surfaces in the bedroom daily. Clean out the drawers regularly.
Mite – Impenetrable Barriers for Bedding
Mites are mobile, crawling through beds and carpets. Plasticised fabrics provide an impenetrable barrier to mites and their excreta.
Washable mite-protective covers for the mattress, bed base, pillows and duvet are available. The modern versions are water permeable and so do not cause sweating.
Bedding & Furnishings
Any furnishings with soft, fluffy surfaces provide growing sites for house dust mites. Similarly they will grow in dust allowed to accumulate about cluttered surfaces and books.
- All bedding should be washable. Synthetic materials, sometimes described as “allergy free” are best. Pillows, blankets and duvets in particular should be washable.
- Soft mattress covers or underlays such as sheepskins should not be used. Kapok or down duvet fillings should be avoided.
- Curtains should be of the type which can be laundered.
- Avoid soft covered furniture in the bedroom.
- Keep all surfaces uncluttered and store books outside the bedroom.
- Carpets are a problem as they can act as a continuous reservoir of mites. While regular vacuuming is helpful it is not as successful as having shiny surfaces such as wood or vinyl.
- Sheepskin rugs provide an ideal haven for house dust mites and so should be avoided.
Even if you dont have an obvious dust mite allergy, you may find you sleep better and feel more refreshed with a good spring clean to get rid of dust mites.