Bed covers ineffective against mites
15 June 2005

Impermeable bed covers provide no significant protection against house dust mite allergy, according to Dutch researchers.

Scientists at the Erasmus Medical Center studied a group of 224 adults who had an allergy to house dust mite, which triggered their symptoms of asthma, rhinitis or dermatitis.

Half of the group were given special impermeable covers for their mattress, duvets and pillows, and the other half ordinary bedding. Group members did not know which type of covers they had received.

In order to test if the covers helped to reduce their allergy symptoms, participants completed a questionnaire at the beginning of the trial, then at its completion, a year later.

Analysing the results, the researchers found no differences in symptom scores between the groups. They concluded that using anti-allergen bedding had no beneficial effect on people with asthma, rhinitis or dermatitis whose symptoms are triggered by house dust mite.

Dust mites are one of the most common triggers for the 5.2 million people with asthma in the UK; they are invisible to the naked eye and most commonly live in bedding and mattresses, feeding on dead skin cells.

'This confirms previous research showing that when the use of impermeable bedcovers was the only measure taken to combat allergy to house dist mite, the covers had no effect in reducing asthma symptoms and did not help people to decrease levels of their asthma medication,' said Josianne Roma-Reardon, Asthma UK's Senior Policy & Information Officer.

'However, this practice may be useful as part of a larger structured programme for controlling allergies,' she affirmed. 'More research is needed to look at what steps people with asthma can take in their homes to minimise their exposure to allergens and help to reduce their symptoms.'

The study is published in the scientific journal Allergy.