Sublingual immunotherapy, also known as SLIT for short, is a form of exposure therapy designed to retrain a person’s immune system to become less reactive to their food allergy. SLIT has been safely used for many years to treat seasonal allergies and recently has been studied for food allergies. Unlike oral immunotherapy (OIT) which is offered in some clinics and involves eating the food, SLIT uses a liquid extract of the food that is held under the tongue to directly access the immune system. Using peanut as the model food allergy, our group at the University of North Carolina has shown that peanut SLIT can increase the amount of peanut a patient can tolerate before having allergic symptoms, something known as desensitization.
In our most recent study published in 2023, 50 peanut-allergic toddlers were treated with peanut SLIT or placebo for 3 years. With an average age of 2.2 years, these children were the youngest ever treated with SLIT. After completing the treatment, 79% of the toddlers getting peanut SLIT were able to eat a serving size of peanut (4443 mg) without allergic symptoms. This is compared to those on placebo who stayed sensitive to peanut and reacted after only 1/2 of a peanut kernel (143 mg). 3 months after the treatment was completed, 63% were still able to eat the serving size of peanut without allergic symptoms showing that the immune changes can be lasting. Although peanut SLIT is not a cure and not able to allow for unlimited eating of peanut, it has the potential to protect against even large amounts of peanut that might be eaten by accident. When combined with its simple 2 minutes a day administration and good track record of safety, we feel like peanut SLIT can be a very promising option for patients with peanut allergy and their families.
Building on this successful research in peanut allergy as well as older studies in milk and hazelnut allergies, we are currently studying SLIT for the combined treatment of cashew and walnut allergies. Our hope and our goal is for SLIT to be expanded to many more foods to ultimately be an option for whatever food or multiple foods a patient may be allergic to.
Desensitization and remission after peanut sublingual immunotherapy in 1- to 4-year-old peanut-allergic children: A randomized, placebo-controlled trial
