Allergies, Asthma, COPD or Emphysema Worst at Night?

Dust mites live everywhere on our bodies where there’s hair and they survive on the skin cells we continually shed in normal living. Although the images portrayed by duct cleaning companies look scary, dust mites are not dirty or pathogenic unless you’re sensitive to the proteins in their bodies and feces. If your asthma or allergy symptoms consistently become significantly worse after you go to bed, it’s worth a simple at home test to see if dust mites are the culprit.

Dust mite populations typically run about 350,000 per square meter in bedding, plus older pillows can be fifty percent dust mites and dust mite feces by weight; again not a problem if you’re not sensitive to them. Washing in hot water and laundry soap will reduce those populations to about five per square meter, but additional steps must be taken. The following simple test will allow you to quickly determine whether dust mites are a significant issue for you.

Dust mite test: Purchase inexpensive four or six mil construction vapor barrier plastic from your nearest building supply store. Place on mattress and tuck in; it’s not necessary to completely seal the bottom of the mattress since dust mites are heavier than air. Place the pillows in plastic bags, squeeze out some of the air so you’re not sleeping on balloons and tape the bags shut.

Wash all bedding to be used that night in 55 degrees C or hotter water and soap. You must use hot water or you’ll just have clean dust mites. Make the bed as usual and if that night your symptoms are significantly reduced, you have your answer.

Long term solution: Since most won’t be comfortable sleeping on plastic every night I recommend purchasing mattress and pillow case covers which are rated as dust mite proof. In my opinion the best types are a very tightly woven fabric with no plastic or vinyl embedded in the cloth. The next best would be the urethane impregnated units. I would never use any bedding with vinyl components due to the toxicity; even if you’ve aired it out for weeks prior to using.

Important note: Because dust mites live in the regions of the body which have hair, they will re-colonize the bedding. Once symptoms start to return you must wash all the bedding including the dust mite proof covers; otherwise there will be no long term allergy control.

Some years ago I read a ridiculous article in a medical journal; JAMA if I remember correctly. In this article they said dust mite proof mattress covers and pillow case covers have no long term benefit to those who suffer. I find it hard to believe the article author wasn’t aware of the fact dust mites re-colonize bedding and need to be washed out regularly, but of course GPs would likely take it at face value and stop recommending this simple drug free solution.


Lindy G. McDonald BSc(Hons), Euan Tovey PhD
Journal of Allergy and Clinical Immunology
Volume 90, Issue 4, Part 1, October 1992, Pages 599-608.
The role of water temperature and laundry procedures in reducing house dust mite populations and allergen content of bedding.

Lancet. 1982 Sep 25;2(8300):675-8.
Reduction of bronchial hyperreactivity during prolonged allergen avoidance.
Platts-Mills TA, Tovey ER, Mitchell EB, Moszoro H, Nock P, Wilkins SR.

The above is not intended as medical advice. As always, consult with your trusted healthcare professionals before making changes to your health regime.

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