More Australian children are allergic to peanuts than in most Western countries – about 3 per cent of Aussie kids compared to 2 per cent for other Western countries.

Parents do everything they can to ensure their child won’t be exposed to peanuts, but there’s always the nagging fear of an allergic reaction due to accidental exposure. Especially when the children are small.

What to do?

One option is peanut oral immunotherapy (OIT) for young children.

This is where allergic children are given very small but increasing amounts of peanuts over a period of time in order to desensitise them against the allergen.

The difficulty with OIT is that it requires following a demanding dosing schedule and involves potential side-effects, including the small but genuine risk of an allergic reaction.

The worst of these sees the child going into anaphylactic shock. The severity of these episodes can complicate attempts to resume the immunotherapy.

Peanut patch

An international study, that included Australian researchers, has trialled a peanut patch on a large group of peanut-allergic toddlers.

In a clinical trial, 362 patients between the ages of one and three were randomly put into two groups: 244 received the peanut patch, and 118 received a placebo patch.

The researchers set a baseline of how much peanut caused a reaction before treatment; 67 participants reacted to less than 10mg of peanut, and 295 reacted to more than 10mg.

By way of scale, one peanut contains 250mg of peanut protein.

How did it work?

This alternative therapy is known as epicutaneous immunotherapy, according to a statement from the Children’s Hospital of Philadelphia.

It involves a patch containing a small amount of allergen that is placed on a child’s back. The patch is changed daily.

This exposes the child’s immune system to a very low level of allergen with much less risk of a systemic reaction.

The goals

There were two goals. It was hoped that the children with a lower baseline (those more sensitive to peanuts) could tolerate approximately one peanut after 12 months of the patch therapy.

For those with a higher baseline (those who would react to more than 10mg of peanut) it was hoped they could eventually tolerate about three to four peanuts.

After a year of treatment, 67 per cent of those wearing the peanut patch were able to tolerate the required peanut dose – compared to 33.5 per cent of those wearing the placebo patch.

In addition, 64.2 per cent of those in the peanut patch group could tolerate three to four peanuts. That was regardless of their baseline at the start of the trial.

Symptom severity was spread evenly across both groups at the start of the trial. But the distribution shifted to less severe symptoms in the group who had been given peanut patches compared to the placebo group by the end of the trial.

Not a cure, but a life saver

This wasn’t about curing the children of their allergies. The hope was to lift the amount of peanut exposure that would accidentally trigger a severe reaction.

Before the therapy, a tiny fraction of a peanut would have triggered a reaction in the participants. After the therapy, in most cases, more than a whole peanut would be required to trigger an adverse reaction.

The study was published this week in The New England Journal of Medicine.