Treating Peanut Allergies

The results have been announced from a major test of a treatment for peanut allergies:

a yearlong clinical trial of an oral immunotherapy regimen that aims to reduce children’s sensitivity to peanut allergens by gradually exposing them to peanut protein over the course of six months, starting with minute amounts that are carefully measured and increased incrementally under medical supervision as tolerance develops.

The goal of the treatment is not to cure the allergy or enable children to eat peanut butter sandwiches, but to reduce the risk that an accidental exposure to trace amounts will trigger a life-threatening reaction in someone with a severe allergy, and relieve the fear and anxiety that go along with severe peanut allergies. . . .

After six months of treatment followed by six months of maintenance therapy, two-thirds of the 372 children who received the treatment were able to ingest 600 milligrams or more of peanut protein — the equivalent of two peanuts — without developing allergic symptoms. By contrast, only 4 percent of the 124 children who had been given a placebo powder were able to consume the same amount of peanut without reacting.

The treatment does not work for everyone. Though only 4.3 percent of children receiving the active drug experienced side effects categorized as severe, compared to less than 1 percent of the children on placebo, 20 percent of the children in the active treatment group withdrew from the study, more than half of them because of adverse events. Fourteen percent of those on active treatment received injections of epinephrine, a drug used in emergencies, including one child who experienced anaphylaxis and required three EpiPen injections. By contrast, only 6.5 percent of those on the placebo received epinephrine.

Slow exposure to gradually increasing amounts is the time-tested way of treating severe allergies, so it's no surprise that this works. I suppose the hard part was finding a way to get started safely, since peanut allergies can sometimes strike because of exposure to freakily small amounts of the protein.

The authors go out of their way to warn against the home remedy version of this, which has spread through motherhood blogs and the like across America and amounts to giving your child a tiny speck of peanut better and gradually increasing the amount. (Which can work, too.) In fact I bet that will come up in the consideration of whether to approve this treatment: sure, it has risks, but it might crowd out the much more dangerous home treatment.