House dust mites

Dust mites live in the dust that builds up around the house, in carpets, bedding, furniture and toys.

You may have heard people talking about being allergic to dust or finding that dust triggers their asthma symptoms. In fact, it's the droppings of house dust mites which cause the problems. These tiny creatures live in the dust that builds up around homes in carpets, bedding, cushions and soft furnishings, for example. They're invisible to the naked eye and 90 per cent of people with asthma are sensitive to them.

Why can they increase your risk of asthma symptoms or an asthma attack?

House dust mite droppings contain substances that can trigger reactions.

How do you know it's a trigger?

You might notice you have more symptoms when dust is disturbed - for example, when you're cleaning, moving furniture or making a bed. Or you might simply find your asthma symptoms are often worse indoors.

What's the best way to reduce the risk of the trigger affecting you?

Take your asthma medicines as your doctor prescribed them

"If your asthma is triggered by dust mites, the best way to reduce asthma symptoms is to look after your asthma and make sure it's well managed, as this reduces the likelihood of you reacting to the dust mite droppings when you come into contact with them - they are impossible to avoid," says Dr Samantha Walker, Asthma UK's Research Director.

Your preventer inhaler works by reducing inflammation in your lungs, meaning they're less sensitive, so less likely to be triggered by dust mite droppings. Help ensure your asthma is as well controlled as possible by taking your preventer inhaler as prescribed, and using a written asthma action plan to help you work out if your symptoms are getting worse, and what to do if they are.

Consider whether you really do benefit from dust mite control methods

People with asthma often tell us what methods they have tried to reduce the number of house dust mites in their homes. These include pesticides that kill mites (acaricides), mattress and pillow case protectors, regular vacuuming, good ventilation, freezing soft toys, 60 degree washes, air filters and purifiers. Some people have told us these methods have helped them, but unfortunately, there's no firm evidence they work.

In fact, research has shown there's not a lot you can do to make a useful difference to the number of dust mites in your home, especially in the UK climate (dust mites thrive in damp environments). So before you start trying methods that can be expensive, take up a lot of time and are hard to maintain, speak to your GP or asthma nurse to find out whether they think it is worthwhile. And if you try these suggestions and it makes no difference to your symptoms, you don't need to continue with them. Your time and effort is better spent focusing on taking your asthma medicines as prescribed, to help reduce your likelihood of reacting to your triggers.

Asthma UK does not recommend ionisers

Ionisers give out electrostatic charges to clean the air but there's no evidence that they improve asthma symptoms. Asthma UK doesn't recommend using an ioniser because some research shows that they increase night time cough in children.

Last reviewed March 2015