Mouse allergy 'to blame for asthma'

Mice have been blamed for some asthma attacks

Research has found that mouse infestation rather than traffic fumes could be partly responsible for high rates of child asthma in cities.

In a study of eight cities, a team from Johns Hopkins University in Baltimore, US, checked the contents of dust samples from the homes of children with asthma.

The team found that 95% of those samples contained mouse allergens, many involving faeces or urine.

We think that doctors need to change their approach to inner-city asthma and take this into account

Professor Robert Wood

Eighteen per cent of the children were then found to be allergic to these and they tended to suffer from far worse asthma.

The number of children suffering from asthma has risen four-fold over recent decades and scientists are unsure about the reasons why.

Various aspects have been blamed - from the increase in central heating and double glazing leading to more allergens circulating indoors, to changes in diet and even the increased general cleanliness of homes.

Routine testing

Many substances linked to pets as well as insects like dust mites and cockroaches may have been contributing to asthma attacks.

Professor Robert Wood, from Johns Hopkins, suggested that the new findings meant many more children with asthma symptoms should be routinely tested for mouse allergies.

He said: "Currently, it is not routine to test asthmatic children for allergies to mice

"We think that doctors need to change their approach to inner-city asthma and take this into account."

It's an interesting finding, but nobody routinely tests for it and they are unlikely to start

Dr Adnan Custovic

Dr Adnan Custovic, a National Asthma Campaign senior research fellow, and an honorary consultant allergist at Wythenshawe Hospital in Manchester, disagreed.

He said that even in heavily infested inner-city populations, it was still less than certain whether mouse, cockroach allergen, or some other potential trigger was to blame.

He said: "It's an interesting finding, but nobody routinely tests for it and they are unlikely to start."

He said that even testing for more commonly accepted allergens such as pet hair and house dust mites was not routinely carried out everywhere.

"People are given half-hearted advice to do all sorts of different things - it's very difficult for GPs, especially as half the population is allergic to something."