A bedside purification system that cleans the air while asthma sufferers sleep significantly reduces their symptoms, a study has found.
The air-filter, Protexo, removes dust particles, pet hairs and powders that can cause inflammation of the lungs and trigger symptoms such as wheezing and tight chests.
Participants in the study, aged seven to 70, reported a 15% better quality of life after a year than those given a dummy machine.
Asthma specialists recommend that the device is made available on the NHS, claiming that the £400 machine will pay for itself with the amount of money that will be saved in hospital treatment costs.
Professor John Warner, a consultant paediatrician at St Mary's Hospital and professor of paediatrics at Imperial College London, who led the research, said:
"This device makes a significant difference to people's lives, with an effect as big as very expensive treatments, and it helps prevent the triggers of the disease."
Participant, Annabelle Abrahams, 14, from Westcliff-on-Sea, Essex, who has had asthma since she was four said:
"I slept badly because I couldn't breathe, doing PE or running around with my friends was difficult and I had asthma attacks if I laughed too much.
"My schoolwork suffered because I was tired and off sick a lot."
The machine has enabled Annabelle to sleep through the night without coughing.
"I've seen a dramatic change and real improvement in my asthma," she said. "I sleep better, have fewer chest infections and enjoy PE and sport."
The machine, which is not yet available for private purchase, costs around £2,000 for six months’ use.