Ten-year-old Dominic Joannou-Scott has suffered from asthma for most of his life, and over the last two years it has got steadily worse. Until, that is, a few months ago, when he found what seems to be a miracle cure. Dominic, who used to wake up wheezing every morning "like an old bloke on 40 a day", according to his mum Helen, is now so different you would hardly know he was asthmatic.
But this is no amazing drug breakthrough. The magic ingredient is a top-of-the-range vacuum cleaner, some new dusters and a lot of elbow grease. According to Dr Glenis Scadding, consultant allergist at the Royal National Throat, Nose and Ear Hospital in London, as many as 40% of child asthma sufferers could reduce their symptoms dramatically by having an old-fashioned spring-clean at home.
At the moment, says Scadding, most of Britain's 5.1 million asthmatics - 1.4 million of whom are children - are treated for the symptoms of asthma, not its cause. A couple of decades ago, they would have undergone a series of skin-prick tests to isolate the allergens that triggered their asthma: today, only 4% of newly diagnosed youngsters are given this option. For while the number of patients has soared, the number of allergists has dwindled: there are currently only 27 across the country. "Which means we serve a population of two to three million people each," says Scadding. Instead, most asthma patients are treated by their GP or an ENT specialist. "What they get are inhaled steroids, but they don't alter the underlying problem - in fact, no one is even looking for the underlying problem," says Scadding.
When asthma patients are allergy-tested, the number-one enemy is the house dust mite - or, more precisely and unpleasantly, its faeces. House dust mites are everywhere in today's central-heated, unventilated, carpeted homes. Most people assume contact with them is an inevitable fact of life. But not Scadding. She argues that there has not been enough research into the effect of reducing the dust mite population on asthma symptoms, which is why she has agreed to take part in an unscientific but fascinating television experiment for Channel 4, How to Beat Your Kid's Asthma, to find out whether having a clean house could reduce the symptoms of 10 young asthma sufferers, among them Dominic.
Helen and Dominic live in a two-bedroom house in Hertfordshire with their cat, Jessie. Dominic's bedroom is a quintessential 10-year-old's hangout, with toys and computer games littering the room, a duvet thrown across the bed and a carpet on the floor. After Dominic tested positive for the house dust mite, Dr Scadding ordered a complete overhaul.
First to go were the carpets and curtains in Dominic's bedroom, replaced with a laminate floor and blinds, which would not harbour dust mites and would be easier to keep clean. Next, an industrial cleaning company gave the house an epic once-over, with every inch damp-dusted and steam-cleaned.
Dominic had also tested positive for cat hairs as an asthma trigger, so Jessie had to be billeted in a cattery.
"We were told we had to leave Dominic's bedroom window open a bit during the day to keep his room ventilated, because that helps keep the dust mites down," says Helen. "And the mattresses were covered with special anti-allergenic covers. During the day, we were told we shouldn't leave the duvet on the bed, because dust mites like a warm, damp atmosphere: we had to drape it over a chair so it got aired."
Every family involved in the programme found there was a marked improvement in their child's symptoms. "It was remarkable, and almost instant," says Helen. "Dominic would rarely have a good night's sleep, and he'd always wake up coughing and wheezy. But the changes in his room and the cleaning made a huge difference literally overnight: suddenly he was able to sleep through and he was waking up able to breathe normally. It's made a difference to everything: he's a lot more relaxed, he's sleeping better so he's more rested and in a better mood, and most of all he isn't coughing and wheezing and bringing up phlegm."
Clearly, Dominic cannot spend his life in a dust mite-free bubble: at school, for example, he encounters dust and occasionally gets wheezy there. He also tested positive for pollen as a trigger, so during the summer his asthma is likely to return.
All the same, argues Scadding, it is surely worth the Department of Health considering investing some cash into a dust mite-busting kit for families with am asthmatic child. "The changes we made cost around £700 per patient," she says. "It's a lot cheaper than a hospital admission."
It is not that simple, says a spokesperson for the NHS: "Not all asthma is caused by allergy to house dust mites - for many people with asthma, this treatment would not be effective. Recent research has also questioned whether control of mites provides benefits even to those patients whose asthma is attributed to them."
Martyn Partridge, professor of respiratory medicine at Imperial College, says more research is needed. "Allergen-avoidance is an exciting area," he says. "But at the moment, major scientific studies have given much iffier results than this programme."
His worry is the guilt factor: how, he asks, will it make parents feel if they believe it is their hygiene standards that are contributing to their child's illness? He is also concerned about asthmatics watching the programme deciding to keep their houses cleaner and then thinking they can do without their preventer inhalers as a result. "We've got very good, scientifically-proven medications for dealing with asthma, and we've had huge success in reducing the number of hospital admissions over the last few years because of them. I'd hate to think anyone was going to think they could do a spring clean and stop using their inhaler."
· The Dispatches series How to Beat Your Kid's Asthma starts tonight on Channel 4 at 9pm.