A peanut patch could help subdue allergic reactions in kids with nut allergies, according to a late-stage clinical trial conducted by an international team of researchers.
Wearing the patch for 12 months effectively desensitized toddlers with mild allergies to peanuts, meaning they could tolerate eating a small number of peanuts without allergic symptoms.
The trial, led by pediatric allergy specialist Matthew Greenhawt from the Children’s Hospital Colorado, was conducted on toddlers aged 1 to 3 years in eight countries across the US, Australia, Canada, and Europe.
Two-thirds of the 244 children who wore the skin patch became desensitized to peanuts, compared to one-third of the 118 toddlers in the placebo group (who likely outgrew their allergy over a longer period of time, as some kids can).
The trial results “are very good news for toddlers and their families as the next step toward a future with more treatments for food allergies,” writes Alkis Togias, an allergist-immunologist at the US National Institute of Health, who was not involved in the trial.
Kids were considered desensitized if they could tolerate the equivalent of about one to four peanuts after treatment – enough to protect them from accidental exposure.
For many families, this kind of protection would offer immense relief from the angst of living with a food allergy. It takes a serious toll on young kids and their caregivers, who are on high alert for any trace of nuts or foods they are allergic to.
“Families have indicated that treatments protecting their children against reactions from unintentional peanut exposures would improve the children’s socialization and the quality of life of the children and their families,” writes the team of researchers.
The patches are designed to expose children to small, controlled doses of a known allergen, in this case, peanut protein, through the skin. Knowingly exposing allergic kids to their kryptonite sounds risky, but emerging evidence suggests it just might work.
Our understanding of kids’ food allergies is fast evolving. A lot of research is coming out of Australia, the food allergy capital of the world, where studies have found that one in ten infants has a food allergy.
Although researchers don’t know why rates of food allergies are rising in countries like Australia, they have a few theories: it could be related to environmental factors, such as low levels of vitamin D, or changes in the gut microbiome as a result of fewer childhood infections.
Kids with eczema also have higher rates of food allergies, and mounting evidence suggests this may be because they were exposed to allergy-causing foods through the skin before eating them, confusing the body’s immune system into thinking food is harmful.
Allergy specialists have also come to understand there’s a small window in which to intervene to head off food allergies. In Australia, like the US, parents are now advised to introduce known foods allergens such as peanuts into their babies’ diets, rather than avoiding them, to ‘nip allergies in the bud’.
But for children who develop a food allergy, there is no cure – and no approved therapies for kids under four years old. Research also shows about two-thirds of young children don’t outgrow their peanut allergy by the age of six. Hence why there is so much interest in developing a therapy for kids’ food allergies.
“The lovely thing about [a skin patch] is it is much, much, much safer than taking something orally,” Murdoch Children’s Institute pediatric allergist and co-author Kirsten Perrett said when speaking at a conference last year about new therapies in the works for food allergies.
The doses of allergens applied in a skin patch are far lower than doses used for oral immunotherapies (essentially crushed-up peanuts taken in a tablet form). And although children may still develop some skin irritation or adverse reactions, patches are a much simpler – and potentially safer – alternative to oral immunotherapy, which involves arduous treatment schedules.
Results from trials testing oral immunotherapies have been mighty encouraging. One kind of oral immunotherapy for peanut allergy has been approved in the US, but it’s only for kids older than four, and oral immunotherapy remains controversial because it carries a high risk of serious allergic reactions.
The safety of peanut patches is also under close watch. Four toddlers in the patch trial experienced an anaphylactic reaction related to the patch; one child pulled out of the trial while the other three resumed treatment without reacting again.
How long a child would have to wear a patch to ensure lasting benefit is also a big unknown that other trials are exploring.
If future trials can replicate the study findings, and show that peanut patches are a safe option that fairly balances the risks of a reaction in a few children with the benefits of many more kids being able to tolerate peanuts in small doses, then we might be onto a good thing.
The study was published in the New England Journal of Medicine.