Doctors in Britain are closer to finding a cure for severe nut allergies, according to a study published Friday.

A research team at Addenbrooke's Hospital in Cambridge exposed children gradually to tiny amounts of peanuts over six months to build up their tolerance.

It is the first time such a desensitization program has been used to treat a food allergy.

Four children — who risked fatal anaphylactic shock from contact with traces of peanut — took part in the study published in Allergy.

The children were initially given a dose of five milligrams but by the end were able to tolerate 880 milligrams — equal to five peanuts.

"We've shown it works. We've shown it can be done safely. Now we're at the stage where we need a larger trial and perhaps a control group, so that we can show it has a large effect," said Dr. Andy Clark, the study's lead researcher.

The research provides hope for the one in 50 young people in Britain with a nut allergy, he added.

"Every time people with a peanut allergy eat something, they're frightened that it might kill them. Our motivation was to find a treatment that would change that and give them the confidence to eat what they like," Clark told the Guardian.

Thirteen-year-old Carl Morris took part in the study.

"I got pretty scared when I was eating things with traces of nuts, but now I can just freely explore different foods that may have killed me before," he said.

Kate Frost is the mother of a nine-year-old boy who participated in the study.

"It's very hard to describe how much of a difference it's made, not just in Michael's life, but for all of us," Frost told the BBC.

"A peanut allergy affects the whole family. You can't go out to a restaurant. If your child goes to a birthday party, he takes a packed lunch."

It's estimated that more than 150,000 Canadians suffer from peanut allergies. About two per cent of people can have an anaphylactic reaction to an allergen, and peanut allergies account for 50 to 100 deaths in the United States every year.