What are dust mites?

Dust mites are so tiny you can’t see them without a microscope. They belong to the same family as spiders. They feed on discarded human skin, house dust, and other microscopic food sources such as pollen and fungal spores.

Dust mites do not bite or sting. However, some people are allergic to dust mites and their droppings. They may trigger symptoms in people who are allergic to them and have:

• asthma
• allergic rhinitis (hay fever)
• eczema

Not everybody with these conditions are allergic to dust mites. But if you have symptoms all year long, you are likely to have a dust mite allergy.

Where are dust mites commonly found?

Dust mites thrive in homes with higher humidity levels and constant warm temperatures. So, they are more common in coastal areas of Australia than in inland, dry areas.

Dust mites live in:

• carpets
• bedding
• clothing
• upholstered furniture

Dust mites live in the bottom of the carpet. They seem to flourish in low traffic areas like under the bed.

Because they feed on discarded skin cells, they are also commonly found in the bed and bedroom. When you are making your bed, they can become airborne and settle in other areas of the house.

How do dust mites affect my health?

People who have asthma, eczema, allergic rhinitis (hay fever) or other allergies may be allergic to dust mites. The allergen created by dust mites can trigger symptoms.

If you suspect that you are allergic to dust mites, you should see your doctor. It’s important to confirm that dust mites are a trigger for your asthma or allergy.

Allergy tests such as a skin prick test or specific blood tests will help to show this. However, a positive test doesn’t mean that the dust mite will trigger your symptoms.

What are the symptoms of dust mite allergy?

If you’re allergic to dust mites, your symptoms will depend on your diagnosis. This could be:

• asthma
• eczema
• hay fever
• another allergic condition

Your doctor will work with you to help control your symptoms. This may involve asthma or allergy medicine, as well as avoiding the dust mites.

In some cases, your doctor may prescribe allergen immunotherapy. Allergen immunotherapy changes the way your immune system reacts to allergens.

This involves slowly increasing doses of the dust mite allergen to help reduce the severity of your symptoms. This can take 3 to 5 years of treatment to be effective.

How can I get rid of dust mites?

Unfortunately, there is no easy way of removing dust mites from your house. You will need to do more than one thing to lower the number of dust mites and see an effect.

The allergen is present both in the mites as well as in their droppings and discarded skin cases. So, it’s important to try to reduce all of these to control allergic symptoms.

In my bedroom

Reducing mites in your bedding is the most effective way of reducing the amount of the allergen in your home.

This is because:

• you spend a lot of time in your bed
• high concentration of mites and their faeces in your bed

Wash your sheets and pillowcases every week in water hotter than 60°C. This will kill the dust mites and remove the allergen. If you can’t use hot water, try a commercial washing product. This should contain tea tree or eucalyptus oils. These both kill dust mites and can be used in cold water.

Open the curtains and allow sunshine into your room and, if possible, onto your bed. Dust mites don’t like bright light.

Put dust mite-resistant protective covers on your mattress, doona and pillows. These should be washed every 8 weeks.

Remove sheepskin underlays from your bed.

Remove pillows and soft toys from the bedroom or wash them every week. Soft toys can be put into the freezer to kill the dust mites, but this will not remove the allergen.

In other rooms

Vacuuming should be done weekly. While it won’t completely remove all dust mites or allergens, it will reduce their numbers. As vacuuming disturbs the dust try to get someone else to vacuum. You should avoid entering the room for 20 minutes afterwards.

High efficiency particulate air (HEPA) filter vacuum cleaners may remove more allergen than a standard vacuum cleaner.

Vacuuming is not very efficient at removing mites and their faeces. Vacuuming alone will not make a significant difference to the number of mites.

It’s more effective to vacuum dust mites and droppings from hard surface floors.

Use a damp or electrostatic cloth to dust hard surfaces.

You can also reduce the overall humidity of your house and increase the air flow. This may help to keep dust mites at a lower level.

If possible, use vinyl or leather lounges rather than fabric.

Replace fabric curtains with venetian blinds or shutters to make them easier to clean. If you can’t do this, try to wash your curtains regularly.

Consider replacing carpets with hard floors. This is more effective at reducing total numbers of mites than vacuuming your carpets, but it is impractical for most people.

Other ways of reducing dust mites

Some commonly promoted ways of reducing dust mites are expensive. There’s often little evidence to support their claims of success. It’s a good idea to discuss these strategies with your doctor first.

Resources and support

To learn more about dust mite or other allergies, visit the Australasian Society of Clinical Immunology and Allergy (ASCIA) website.

Alternatively, call Healthdirect on 1800 022 222 to speak with a registered nurse (known as NURSE-ON-CALL in Victoria).