AAIQ   The Association of Allergists and Immunologists of Québec

Dust mite allergy

acarien

A dust mite (magnified)

Fecal materials from dust mites represent an important reservoir of allergenic proteins from dust mite species: Dermatophagoides pteronissinus (Der p) and Dermatophagoides farinae (Der f).

Dust mites feed on particles of (our) dead skin.

They are found therefore in abundant quantities in areas where we spend a lot of time: on mattresses, carpets, upholstered furniture, stuffed animals...the allergenic proteins of dust mites are also found in the air of our houses, but only when we kick up the dust (such as when we pass the vacuum cleaner, shake the carpets, etc.) They only remain in the air for short periods of time. Dust mites represent the principal allergen found in house dust. A humidity level of 50% or greater encourages proliferation of dust mites. Here are the recommendations for reducing your exposure to this type of allergen:

- Control humidity in the house, ideally 45% or less. It is possible to purchase a hygrometer to measure the humidity level. If you find the humidity elevated and your house is not equipped with a central air exchanger or dehumidifier, you might wish to acquire a stand-alone dehumidifier.

- Minimize floor carpet, especially in the bedrooms. If this is not possible, you may treat carpets regularly with an acaracide agent (benzyl benzoate).

- Minimize upholstered furniture; instead opt for leather furniture.

- Eliminate stuffed animals. If necessary, your child may keep ONE, but this should ideally be washed in hot water each week. If you can't wash it, you can put it in a plastic bag and then in the freezer for several hours.

- Wash the sheets, all the blankets and comforters in hot water (only hot water kills dust mites) as often as possible (every 2 weeks, minimum). If it is not possible to wash certain blankets or comforters, these should be enveloped in dust mite proof covers with a zipper as closing mechanism.

- Use dust mite-proof mattress and pillow covers: these can be found in most department stores. They must be dust mite-proof and have a zipper as a closing mechanism. They may also be found on the internet and in medical and other specialty stores.

- Clean the floors once a week (using a vacuum cleaner with a HEPA filter).

- A stand-alone HEPA air filter might offer some additional benefit.

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Simon Hotte, MD FRCPC
(translation: Andrew Moore, MD FRCPC)