Liquid mouth drops could one day protect people from peanut allergies
The treatment may rival a similar approach that involves swallowing the food
A no-fuss immune therapy involving liquid drops placed under the tongue could protect people with peanut allergies from reacting if exposed.
Results from a small study of the treatment — called sublingual immunotherapy, or SLIT — rival those of a similar treatment that also builds allergy tolerance by exposing sufferers to small, daily doses of an allergen, researchers report September 4 in the Journal of Allergy and Clinical Immunology. But in that approach, called oral immunotherapy or OIT for short, doses are swallowed rather than administered under the tongue (SN: 11/18/18).
The question with SLIT “was always about efficacy,” says Brian Schroer, director of allergy and immunology at Akron Children’s Hospital in Ohio, who was not involved with the research. The new study “shows it’s pretty much equivalent to OIT in terms of protection from accidental food exposures,” he says.
SLIT’s delivery method through the mouth’s mucous membrane means that much smaller doses can be used than with the oral treatment, says Edwin Kim, a pediatric allergist and immunologist at the University of North Carolina’s School of Medicine in Chapel Hill.
SLIT also produced milder side effects, such as a mouth itch that lasted for up to 15 minutes, compared with OIT, which occasionally has caused allergic reactions that required epinephrine, Kim and colleagues report. And while patients need a two-hour rest period after taking the oral treatment, those receiving a sublingual dose need only hold it under their tongues for two minutes. And “then you’re in the clear to go about your day,” Kim says.
Still, the SLIT approach isn’t quite ready for prime time until it can be tested further in larger studies, says pediatric allergist Christina Ciaccio at the University of Chicago School of Medicine. She was not involved in the new research, but has helped to run studies for companies developing other peanut allergy treatments. But “would I fault someone in private practice for trying it in the right patient? Probably not,” she says.
Food allergies affect nearly 8 percent of U.S. kids and 11 percent of adults, estimates suggest. A study in 2010 suggests that the number of known peanut allergy cases tripled, for unclear reasons, from 1997 to 2008. Today, an estimated 2 percent of kids are allergic to peanuts.