A NEW 'mite proof' bedding fabric can reduce allergic asthma symptoms by up to 50 per cent, according to research from Southampton University. Intervent, from the company that produces the wet weather fabric Gortex, is made of a soft 'breathable' plastic with pores too small for the mite allergen to penetrate. Zipped over pillows, mattress and duvet, with normal bedding on top, it has also been shown to reduce symptoms of eczema and rhinitis.

The only drawback is the cost: a full set of covers for a double bed costs about pounds 300. Similar cheaper products are available but have not been so fully tested.

Allergy to the house dust mite is thought to cause about 80 per cent of asthma cases. For more details, freephone 0800 515 730.