Peanut allergy: 'Life-changing' study helps severely allergic children to build up tolerance

Parents of children with severe allergies have hailed “life-changing” research showing it is possible to build up a tolerance to peanuts and reduce the chances of potentially fatal attacks.

The “ground-breaking” international study involved the Evelina Children’s Hospital in London and used a peanut extract to steadily build up exposure in children who couldn’t tolerate one-tenth of a peanut at the start of the trial.

It marks the largest and most comprehensive finding to date and found two-thirds of young people who took part increased the levels of peanuts they could safely swallow – improving their tolerance by 100-fold on average.

This could significantly decrease the risk of a life-threatening allergic reaction in the event that they are given food without clearly labelled allergens, something that has caused deaths in two tragic cases recently.

It is already having a transformative effect for the families involved, like the parents of six-year-old Emily Pratt who was diagnosed with a severe peanut allergy at the age of just one.

“The study has completely changed our lives,” Emily’s mother Sophie Pratt, 44, from Kentish Town, London 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.

“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.”

Emily was enrolled in the Peanut Allergy Oral Immunotherapy Study of AR101 for Desensitization (PALISADE) study, which involved 496 children aged four to 17 and has a UK-arm run by King’s College London and the Evelina.

Two-thirds of the participants received capsules containing a protein molecule found in peanuts known to be a key trigger of allergic reactions, while the rest were given a placebo pill.

The concentration of the protein was increased every two weeks for six months under medical supervision, with another six months at a ”maintenance dose”.

The findings of the trial, published in the New England Journal of Medicine on Sunday, reveal 67 per cent of the participants could tolerate at least 600mg of peanut protein, the equivalent of two whole peanuts, without a reaction. This compares to just 4 per cent of those on the placebo treatment.

Half of the participants could consume the equivalent of four peanuts, while Emily can now manage seven peanuts without adverse reaction.

“We can now let her socialise with friends and do all the normal things that other children do,” Ms Pratt added.

“The results of this ground-breaking study are very promising and suggest that we will be able to protect children who are allergic to peanuts from having a severe reaction after accidental exposure,” Professor George du Toit, paediatric allergy consultant at Evelina London and the UK chief investigator for the study, said.

“This is extremely good news as the number of children being diagnosed with a peanut allergy in the UK has more than doubled over the past two decades.”

A peanut allergy affects one child in 50 in the UK at present, and allergies are rarely grown out of, meaning the only treatment is education on strict peanut avoidance.

“Families live in fear of accidental exposure, as allergic reactions can be very severe, and can even lead to death,” Professor du Toit said.

The risks have been driven home in the recent case of 15-year-old Megan Lee who was fed a meal with “widespread presence” of peanut protein despite alerting the kitchen to her allergies.

Her death led to the restaurant bosses in Lancashire being convicted of manslaughter by gross negligence in October.

Sandwich firm Pret a Manger was also at the centre of an inquest over the death of Natasha Ednan-Laperouse, also 15, who suffered anaphylaxis after eating a baguette which had sesame oil in it despite no warnings on the packaging.

In the Palisade trial participants were closely monitored to manage any anaphylactic shock.

Though mild allergic reactions were more common in the placebo group, severe reactions affected 4.3 per cent of the peanut group compared to 0.8 per cent of those receiving a placebo, and 59.7 per cent and 44.4 per cent, respectively, had a moderate reaction.

“This is not a quick fix, and it doesn’t mean people with peanut allergy will be able to eat peanuts whenever they want.” said allergist Dr Jay Lieberman, a co-author of the study at the University of Tennesee. “But it is definitely a breakthrough.”