Asthma sufferers might as well stop wasting energy and money on labour-intensive or costly interventions to get rid of household dust, for a study has found that specialist equipment are of little use."We can conclude with confidence that there is no need to buy expensive vacuum cleaners or mattress covers or to use chemical methods against house dust mites, as these treatments do not work."
"If you are wondering why it is that mattress covers and the other strategies are not effective, the likely answer is that all these treatments do not have a large enough effect on the occurrence of allergens from house dust mites."
"The level of allergens is so high in most homes that what remains after the treatment is still high enough to cause asthma attacks," said the study’s lead author Peter Gotzsche.
The researchers at Nordic Cochrane Centre in Denmark reviewed 54 earlier studies, involving 3,000 asthmatics, and concluded that no chemical or physical intervention to reduce exposure to house dust mites is effective.
Studies, which ranged from about two weeks to two years’ duration, employed a variety of interventions. Some researches used chemicals to kill mites, while others used physical interventions such as encasing mattresses and pillows in covers that mites cannot get through.
Other studies called for frequent laundering of bed linens in hot water or bleach; beating cushions outside; and removing toys, plants and furniture from a home.Although it seems counterintuitive that such intensive efforts to control dust mites were unproductive, the findings are consistent.
"It is better not to waste money on interventions that don’t work. Even very low allergen concentrations can affect bronchial distress among sensitive dividuals, and most homes host many mites and mite allergens."
"In addition, mite-sensitive individuals are often sensitive to other allergens, so that successful elimination of a single allergen might have limited benefit at best."
"Some of the included studies had obtained reductions of more than 50 per cent, and some more, but even reducing environmental allergens by 90 per cent is insufficient," the British media quoted Gotzsche as saying.