Erin Fenton, 33, doesn’t remember a time when she wasn’t allergic to peanuts. It all started with a fateful bite of a cookie when she was 11 months old that caused her to break out in hives and a coughing fit (or so she was told).
After some testing, she was diagnosed with a peanut allergy. It was severe enough for her to carry an EpiPen at all times. Otherwise, the advice from her doctors was just to avoid peanuts and anything that was unlabeled and could possibly contain them.
“There are so many worse things health-wise that could happen, but going to school when there were birthday treats, I wouldn’t eat the birthday treat,” Fenton said. She sat at the “peanut-free” table at lunch, which could get lonely on the days her friends brought PB&Js and had to sit elsewhere. Out of an abundance of caution, she’s never been to a baseball game.
All of these things felt relatively manageable until she began thinking about starting a family in her mid-20s — and didn’t want her allergy to impact her future children. “I [was like I] don’t really care about eating a Reese’s peanut butter cup. I do care about my children being able to do those things,” Fenton said.
When her allergist told her about an allergy desensitization method called sublingual immunotherapy (SLIT), she was hopeful. SLIT is done by placing allergen-containing drops under your tongue, and can often be done at home after the initial dose in an allergist’s office. The goal is to work up to higher doses over time so that your body no longer reacts so strongly to the allergen.
After her allergist ran skin and blood tests to confirm her allergy, once a week for six weeks, Fenton received a bottle of diluted peanut solution. (While the Food and Drug Administration has approved SLIT tablets for certain environmental allergies, there are no approved products in this category for food allergies; the drops are custom compounded.) She’d put a drop under her tongue every day for a week, then head to the allergist to check in and up her dose until she reached the maintenance dose.
At this point, Fenton was told she would have protection against accidental ingestion equal to one peanut — and could alleviate stress about sitting near someone eating them.
It seemed to work. She was finally able to sit in a conference room while someone ate peanuts without having anxiety that she might have a reaction. Now, she even packs her kids’ favorite peanut puffs in their lunchboxes.
How allergy desensitization works
Allergy desensitization treatments such as SLIT target IgE-mediated food allergies. These occur when your immune system wrongly thinks a food protein (like those in a peanut) is dangerous and produces antibodies called immunoglobulin E (IgE) against it, causing a rapid — and sometimes life-threatening — reaction. (Non-IgE-mediated food allergies, which typically cause gastrointestinal symptoms, are driven by different immune responses.)
The theory behind these therapies is simple: By exposing yourself to small, increasing amounts of an allergen, your immune system becomes less reactive to it over time.
“Accidental ingestion” protection is typically the end goal with any food allergy desensitization protocol, since there’s no “cure” that would allow someone to consume their allergen freely, said Kaoru Harada, a board-certified allergist and immunologist at Yale Health who studies both environmental and food allergies.
“Say someone has a peanut allergy, they can’t just go eat a peanut butter sandwich, but hopefully it would protect them against cross-contamination if they’re at a restaurant or a buffet and they accidentally used the same cutting board or things like that,” she said.
Some research suggests remission (desensitization that continues for months after stopping therapy) might be possible for some people — the data is strongest in very young children who start these treatments early. But researchers are still trying to figure out if these therapies have the potential to create permanent, long-term tolerance and, if so, who the best candidates are and what the ideal protocols would be.
Types of therapies available for food allergies
Over the past five to 10 years, desensitization therapies for food allergies have become more prevalent in clinical practice, said Jennifer Dantzer, a pediatrician at Johns Hopkins Medicine who conducts clinical and epidemiological research around food allergies.
Here’s how the options stack up.
Sublingual immunotherapy
SLIT can be done using drops or tablets that contain very small doses of an allergen. Drops that go under the tongue, like the ones Fenton described, are currently in-use, and Dantzer said there’s a dissolvable tablet in clinical trials.
The drops themselves are also typically compounded, or custom made for each person, since there’s no FDA-approved SLIT product.
Treatment is not standardized and may differ from practice to practice. Typically, you will go to your allergist’s office for the first dose, keeping the drop of liquid under your tongue for a couple of minutes before swallowing or spitting it out. If all goes well, you’ll continue with a daily dose at home, gradually increasing it over weeks or months until reaching a “maintenance” dose that you keep taking indefinitely.
Oral immunotherapy
Oral immunotherapy, or OIT, is similar to SLIT but is done using the actual food in question. The first proof-of-concept study, with patients allergic to eggs, was published in 2007. Today, the general idea is applied to many other foods, though the data is most robust for peanut allergies, Dantzer said.
There used to be an FDA-approved OIT product (a peanut powder), but it was pulled from the market in July 2026 (not for any safety or efficacy issues).
Again, there is no standard protocol that all allergists use, but in general, OIT typically involves three main phases of treatment: First, an initial dose escalation day in the doctor’s office where you are given small amounts of the allergen to find the right starting dose. Then, you enter the buildup phase in which you typically eat it every day, increasing the dose every two to four weeks (as long as no reactions occur). Finally, you enter the maintenance phase, which involves consuming the target dose daily at home to maintain desensitization.
Biologics
Harada calls these treatments a “very exciting new development” in the field. Biologics are drugs that mimic naturally occurring molecules and are designed to target one specific part of the immune system.
One such treatment, an injectable called omalizumab, was approved in 2024 for protection against accidental ingestion and reactions to multiple food allergies. What’s unique about this drug is that it blocks IgE antibodies, Harada said, so it can address any IgE-mediated food allergy and help people with multiple food allergies.
After receiving the first three injections under medical supervision, patients typically self-inject omalizumab at home, she said. The frequency (either every two or four weeks) depends on an individual’s baseline IgE levels and body weight.
Downsides include that biologics can be costly and like with the other treatment options, are not a permanent fix. “With omalizumab for food allergy, at least the way it’s approved right now, if patients stop the omalizumab, that protection is probably going to go away, but there’s a lot of research going into whether there are certain patients where maybe it leads to remission,” Harada said.
Risks and results
For now, if you’re interested in food allergy desensitization for yourself or your child, the first step is to see an allergist. Dantzer recommends discussing logistical details of each treatment option, including frequency of in-office visits, as well as personal goals.
There is a risk, though rare, of having a potentially life-threatening reaction to these immunotherapies, which is why they should only ever be done under the strict supervision of a health care provider who can make sure your dose is appropriate and consider other potential risk factors (such as taking these therapies during an illness). In some cases of very severe sensitivity, your provider may suggest taking omalizumab while doing OIT to reduce the risk of a reaction.
There are some people who aren’t good candidates for desensitization in general, including those with uncontrolled asthma or eosinophilic esophagitis, which is a chronic allergic/immune condition that causes vomiting, trouble swallowing and food reactions due to inflammation in the esophagus, Harada said. It’s also not recommended to start new allergy immunotherapy during pregnancy, though you and your allergist may decide to continue maintenance therapy that you’re already taking and tolerating well.
Dantzer noted that a few other biologics and a patch for pediatric food allergies are currently in clinical trials. Researchers are also studying biomarkers that would indicate someone is in remission and no longer needs a maintenance dose, Harada said.
As for Fenton, she described her experience with SLIT as life-changing. “It’s been really cool to just have this freedom,” she said. She doesn’t have to limit the foods her kids can enjoy. She doesn’t stress if there’s a person next to her on a plane eating peanut butter crackers. And she plans to go to her first MLB game to watch the Texas Rangers play this spring.
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