People with a peanut allergy have been given new hope after a study showed sufferers could build up tolerance to them.
In a year-long trial, children with a severe nut allergy were given increasing amounts of peanut protein.
The youngsters not normally able to tolerate exposure to even a tenth of a single peanut could eventually cope with two whole peanuts, the trial found.
Scientists believe that by gradually building up tolerance levels, allergy sufferers could protect themselves from the sometimes fatal consequences of accidental exposure.
Researchers from Evelina London Children's Hospital and King's College London carried out the study which suggests immunotherapy treatment – used to treat pollen and bee sting allergies – could protect people from potentially fatal reactions.
Almost 500 children aged four to 17 were recruited from the US and Europe by the PALISADE study to take part in the biggest ever peanut allergy treatment trial.
The children were split into groups and were given either a capsule of peanut protein or a dummy powder.
The doses were gradually increased every two weeks over a period of six months.
They were then continued on a "maintenance dose" of peanut for a further six months.
The results, published in the New England Journal of Medicine, discovered about two-thirds (67%) of children and teenagers could tolerate at least 600mg of peanut protein, compared with just 4% of participants on the placebo.
Professor George du Toit, paediatric allergy consultant at Evelina London and the study's chief investigator, said: "Peanut allergy is extremely difficult to manage for children and their families, as they have to follow a strict peanut-free diet.
"Families live in fear of accidental exposure as allergic reactions can be very severe, and can even lead to death.
"Until recently there has been nothing to offer peanut allergy suffers other than education around peanut avoidance and recognition and self-treatment of allergic reactions."
Sophie Pratt, 44, from north London, enrolled her six-year-old daughter Emily onto the study.
Emily has had a peanut allergy since she was one and her mum says the study is life-changing.
"The study has completely changed our lives," she said.
"Before Emily took part we were uncomfortable being more than 20 minutes away from a hospital and she wasn't able to attend play dates or parties without me or my husband being there.
"We had to constantly study food labels to ensure peanuts were completely eliminated from Emily's diet.
"Her allergy was very severe so even a small amount of peanut could lead to a very serious reaction. The impact on our family life was huge."
Peanut allergy has doubled over the last two decades and affects about one in 50 children in the UK.
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People rarely outgrow the allergy which is the most common cause of food allergy deaths.
The PALISADE study was funded by Aimmune Therapeutics, manufacturers of the peanut protein used during the trial.