Doctors in Britain believe they may soon be able to cure children of peanut allergies, by feeding them tiny doses of peanut flour so that they eventually build a tolerance.
Researchers at Addenbrooke's Hospital in Cambridge, U.K., have already tested the treatment on 23 kids. The results of that study grabbed headlines last spring when it was published in the journal Allergy.
Now, the same team is preparing to start a much larger trial, involving more than 100 children, making it the largest study to date on the experimental therapy.
If all goes, well, the researchers hope to be able to begin offering the treatment in about three years through their clinic.
"At the end of three years, we'll have a really clear idea of whether this treatment really works, and whether it's a practical treatment that we could use in clinics," pediatric allergy specialist Dr. Andy Clark, the study's lead researcher, told Â鶹´«Ã½ Channel by phone Monday.
The new study, funded by the UK's Department of Health, will involve 104 children with peanut allergies aged between seven and 15. They will be given tiny amounts of peanut flour every day, starting at about one milligram, added to some yogurt.
"Initially, it will be such a small dose, most of these kids won't react to it," explained Clark. "We then give them this dose to take every day at home. And then, every couple of weeks, we bring the kids back to the research ward and we increase the dose.
"At some point during the dose increase, the children might get a mild allergic reaction, which could be mouth itching or a tummy ache. But eventually, they'll gain a tolerance to the increasing doses, so that at the end of three months of treatment, they mostly will be able to tolerate about five peanuts a day."
That works out to about 800 milligrams of peanut flour.
The first pilot study had good results; at the end of that study, 20 out of the 23 sufferers were eventually able to eat more than 30 peanuts safely.
Clark explained that the experiments are carried out in a very controlled setting, where resuscitation drugs and specialists are available should any of the children develop a serious anaphylactic reaction.
He notes that in the pilot study, there were no serious events. Still, he cautioned that no one with a serious peanut allergy should attempt a do-it-yourself treatment approach.
"Don't try this at home. It shouldn't even be tried in clinics at the moment until we've explored it further," Clark advised.
The researchers aren't sure whether their treatment is a permanent cure, or whether allergic children would need to continue taking the peanut flour to maintain their tolerance.
"We don't have the long-term answer to that," he said. "We hope that in future, we can reduce the treatment, eventually getting rid of it."
But he says even if it only helps children to tolerate more peanut proteins than before treatment, it should reduce some of the worries that allergic kids and their families carry every day.
"The kids who've gone through the pilot study say it's changed their lives," Clark said.
People with peanut allergies can have severe reactions to even tiny amounts of the ground nuts, when their immune systems mistakenly interpret proteins from the nuts as invaders and mount a massive response. The worst case scenario is anaphylactic shock, which can cause a drop in blood pressure, swelling of the tongue or throat and sometimes death.
The trial would be the first successful program of its kind. Previous attempts in the 1990s to cure peanut allergies using injections of peanut compounds were not successful and produced serious side-effects.
Similar desensitizing has been achieved with people allergic to bee and wasp stings and for people with pollen allergies, but no success has been had up to now on food allergies.
It's estimated more than 150,000 Canadians suffer from peanut allergies. Of them, about 25 to 35 per cent are also sensitive to tree nuts, such as almonds. Some children outgrow the allergy on their own but for at least 80 per cent, it's thought that the allergy will be lifelong.
