Fixing peanut allergy by eating peanuts
© 2014 Roy Benaroch, MD
Peanut allergy can be a big deal. And most children who are allergic to peanuts will not outgrow their allergies. Avoidance has been the main way to treat peanut-allergic people, but that doesn’t always work. Peanuts can sneak into foods, especially with young children who may not be able to monitor their intake closely. What if there were an easy way to “cure” peanut allergy?
Researchers in the UK published a study last week looking at the safety and effectiveness of oral desensitization. They enrolled 99 children from age 7-16, all of whom with documented real peanut allergy by prior oral challenge (ie, they had all had serious, immediate reactions to peanut under controlled conditions in the past.) They were randomized into two groups. The control group was told to continue avoiding peanuts. The kids in the intervention group were given a daily dose of oral peanut flour, starting with a tiny dose of 2 mg, and working up every two weeks to a maximum dose of about 5 peanuts worth of protein. Of the 49 children randomized into the intervention group, 6 withdrew from the study—four of whom because of reactions to the peanut. One child required one dose of epinephrine during the study because of a serious reaction. After the study period, all of the remaining participants in both groups had a double-blind, placebo controlled peanut ingestion to see if an ordinary dose of about 10 peanuts could be safely tolerated without a reaction.
Of the children in the control group, who had been told to just continue to avoid eating peanuts, none could then tolerate a peanut ingestion (46 of the 46 who were still participating at that time reacted.) In the exposure arm, about 85% of the participants who completed the oral desensitization scheme were able to tolerate eating peanuts. After the study period, most of the children who had been randomized into the control arm were offered oral desensitization, and they ended up doing about as well.
Though oral desensitization worked most of the time, some questions remain. It’s not known how long these children will remain desensitized—they may need to continue oral exposures daily to prevent relapse back into clinical allergy. And about 20% of the original intervention group didn’t complete the study for a variety of reasons, some of whom because they couldn’t tolerate the treatment itself. But for most of the children who could complete the therapy, oral desensitization seems very promising.
It makes sense, too—we know that early oral exposures to foods seems to prevent at least some kinds of allergies, and that policies that encouraged delaying foods (especially past six months of age) probably led to increased allergy.
However: this is still an area of active research. Please do NOT try this on your own. The research groups had specific protocols using purified proteins, and though it’s likely that widespread use of this technique will lead to a simple, home-based regimen, we’re not quite there yet. If your child has peanut allergy and you’re interested in pursuing oral desensitization, speak with a board-certified allergist about enrolling in a trial or learning more about this before you give your child any peanut.
edit 2/21/2014 — fixed broken link to study