Short Wave - The Closest Thing To A Cure For Allergies

Episode Date: December 9, 2025

More than 100 million people in the U.S. have some allergy each year. That’s about every 1 in 3 adults. For many, the fix is a bandaid: over-the-counter allergy medications. But there’s another treatment that works to lessen these reactions rather than just manage people’s symptoms, allergy shots. The treatment has been around for over a century and is still popular today. Patients have to take the shots for a few years, and it’s the closest thing science has to a cure. Host Regina G. Barber speaks with Dr. Gina Dapul-Hidalgo about how this immunotherapy works and how certain guidelines to keep your child from developing common food allergies have changed.Interested in more science behind allergies? Check out our other episodes:Having a food allergy? And how your broken skin barrier might be the causeSpring Allergies and what to do about themHave another topic on human biology or consumer health you want us to investigate? Email us your question at [e-mail] to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

Hey, shortwavers. Real quick before the show, let's talk about public media. Public media has been in the news a lot this year. And public media is what makes NPR shows like Shortwave special. It's made for you. When you listen to an NPR podcast, the people who make it aren't thinking about shareholders or advertisers, we're thinking about you and delivering on a promise to help you understand the world a little better. From its founding in the U.S., public media was always meant to tell stories from underrepresented communities, providing cultural insight that expands your perspective. At NPR, we still believe all of that. We always will. But as of this fall, federal funding for public media, including NPR and local NPR stations, has been eliminated. And now we're heading into an uncharted future. But we know you won't let public media go away. We rely on your support to bring you shortwave now more than ever. This year, we have loved bringing you stories about what happens inside a top-secret nuclear facility,

whether kids should be taking melatonin, why flowers are blooming early, how nightmares work, and what happens when AI cannibalizes its own data. And we can't wait to bring you more episodes like that in 2026. So thank you if you already go the extra mile as an NPR Plus supporter. If not, you can join the Plus community. Get a bunch of perks like bonus episodes and more from across NPR podcasts. Support public media by signing up for NPR Plus today at plus.npr.org. You're listening to Shortwave from NPR.

Hey, shortwavers. It's Regina Barber with a very important message. I hate allergies. Itchy nose, runny eyes when my throat. get scratchy. It's like my own body is rebelling against me. And it's not just seasonal allergies. My allergies can strike when I'm cleaning the house, when I'm mowing the lawn at any time of year, when I move to D.C. And after too many sneezes, I was like, it's time to take action. What is up with this? So the idea behind allergies is that your body is overreacting to something harmless. Right? So we're not supposed to be allergic to pollens, cats, dogs, foods, drugs. But if you are, you are,

your immune system encounters these allergens, and it's thinking, danger, danger, when it's really something harmless. That's Dr. Gina DePool Hidalgo. I invited her to the NPR Studios because she's a pediatric and adult allergist in the D.C. suburbs. And she very patiently began our conversation with the recap of what allergies are. You usually had to have been exposed to the allergen in the past. And it's that first exposure where your body ends up making allergic antibodies, what we call IgE, or immunoglobulin-E antibodies to those allergens. People's bodies have been doing this, encountering allergens, overreacting, creating these allergic antibodies for a long time,

which means doctors have been trying to treat it for a long time. Most patients, we end up recommending things like antihistamines, nasal sprays, eye drops, really more symptomatic treatments to help decrease your symptoms so you can, you know, be around the allergen and be somewhat okay. Claritin, Zertic, Allegra. They're really temporary kinds of treatment options. But what if I told you there was another kind of treatment that worked for all but the most severe allergies? One that didn't just treat the symptoms of your allergies,

but the actual cause of them. The idea is that you build tolerance over time. By giving you what you're allergic to, you get desensitized to those allergens that you're being treated with. Unlike medicines, which only take care of the symptoms, allergy shots are actually training your immune system. system to react differently when you're exposed to the allergies. So today on the show, allergy treatments.

We're learning where our allergies come from, how they're detected, and even how to treat them, so they're effectively gone. You're listening to Shurwave from NPR. So Dr. Gina, can I call you Dr. Gina? Yes, you can call me Dr. Jeep. Excellent. Let's start with allergies. I was well into my adulthood when I finally did the allergy panel to check if I had.

had allergies? Because I suspected. Can you, for our listeners, tell us how does this test work? Yes. So how it works is that we're actually introducing these allergens into your skin. There's different forms of testing, but the main common one is what's called a skin prick. Yeah, it looks like a meat tenderizer just boom on your skin. Right on the skin. Yeah. So the idea is that by exposing your skin to that, if your body has made those allergic IgE antibodies, it recognizes it, it binds to it, and then within 15, 20 minutes, you get a little red, itchy spot at the sight of where those allergens are. Yeah, I found out I was allergic to. Let me read this, starting from most intense to least intense. Basically all grasses, dust mites, some tree pollen and weeds, cats, I have four cats, cockroaches equal to cats, feathers, mosquitoes. What's happening in my body when I encounter these allergens?

So what happens when you encounter the allergen is that your body is exposed to that allergen. Let's just use cat, for example. And then the IGE is waiting for its partner. And then it binds to that allergen. That IGE, again, is an immunoglobulin E, which is the allergic antibody. And then within 15, 20 minutes, it releases chemicals like histamine, prostate, glandins, leukotrienes. It's these chemicals that actually cause the symptoms that are related to allergy within 15-20 minutes. Like the itchy, the water. Yes, itching, congestion, sneezing, all of that. So why am I not bothered by my four cats? Like, I've had four cats for the last year and a half, and I'm just not that bothered by it, but it's like in the middle of my,

my allergy spectrum of like, of reactivity. Of reactivity, yeah. God. So the fact that you don't have symptoms means that you might not have a clinical allergy or clinical significance to the allergy test, but you're primed for it. So there may be certain breeds of cats, for example, that you might have issues with. Yes, and maybe not necessarily your cats. So it's the idea of you've made these allergic antibodies that are waiting on your mass cells. And then when you are exposed to it, there are certain ones that may say, oh, I'm going to be releasing my histamine from these mass cells and cause the symptoms.

So the way to see it is that you are sensitized, meaning you were exposed to it, your body made those allergic antibodies. But now not everybody actually has a clinical reaction, but a majority of people do. Oh, wow. I was also fascinating. I asked the doctor this, the allergist, I do feel like a little bit bothered by them, but not a lot. And he's like, well, you'll notice if you go on a long trip and come back. So why is that? So we have people, you know, who really experienced that.

For example, you lived with a cat, and then you go, off to school and then you come back home and all of a sudden like to college. Yes, to college and then you know you come back home for break or the summers and you're like, oh my goodness, why am I having this? You know, the opposite of allergy is tolerance. Yeah. So when you're exposed to something quite frequently, then you're not going to be allergic to it because your allergic antibodies are not going to be, you know, releasing these chemicals all the time. So if you are around something, then it's likely that you're more tolerant to it than allergic. But that panel still picked up that I am allergic to cats.

I wouldn't say allergy necessarily, but that you're sensitized to it. So this is where this idea of like allergy immunotherapy, basically exposure therapy through allergy shots comes in. After I did that allergy panel, we were talking about, the allergist came back and he was like, oh. And he was like, wow, you would be a great candidate for allergy shots. And I had never heard of these shots before. So can you tell me a little bit about the history, like who first came up with these allergy shots and when? So it was actually introduced over 100 years ago. So in 1911, a brave British physician named Dr. Leonard Noon started purifying the grass extracts because he hypothesized that there's some toxin.

They used the word toxin back then, that there was some kind of toxin that was causing these symptoms. and that by inoculating these patients with increasing doses of grass pollen, that it would decrease the symptoms and desensitize them. And so those were the first reports in the early 1900s that allowed us to see what we now call allergen immunotherapy and allergy shots. That's the history behind when it started. Yeah. And in its sense developed. So how has it changed then as time has gone on? So now it's more refined. Yeah. There are actually companies that make the allergen, you know, they grow the pollens, they go the plants, and it's purified and extracted so

that it's much more refined than when it was many, many years ago. Got it. Okay. So can you tell our listeners how that process works? Like, it's not just one shot. It's a series of shots. Yes. So there's different protocols, but exactly what you're going through is the typical, you know, standard schedule. So the idea is that you're starting off with very dilute doses, and then you come once a week for several months. And then at some point when you reach this target dose or maintenance dose, then you can come every two to four weeks depending on the protocol. So it's two phases, what we call the buildup phase, which is all that going once a week, coming, coming, and then there's the maintenance phase, which is then the once every four weeks. And the idea is once you

get to that maintenance dose, the amount that's in that maintenance dose has been calculated so it contains the amount that has been shown to be effective. But does it always work? Like, am I cured? Like, do I have to do shot every month for the rest of my life? No. So this is something we get asked all the time. So the idea is that by getting to the maintenance dose,

you actually, we recommend about a three to five year therapy. Of just going once a month. Yes. And there is no cure for allergies per se, which is why we can't say this is going to cure you. I was telling everyone that. I'm like, these shots are going to cure me. And they're like, no.

The closest thing to a cure. But in general, it's long-lasting effect. And I have had some patients who did this years ago. Because, right, this has been out for over 100 years. Some that did this in their middle elementary school. They'll come back to me in their 60s and say, oh, Dr. Gina, I want to start shots again because I feel like my symptoms have come back. So in that case, that was decades of being, you know, asymptomatic to their allergen.

So again, it's very individualized, which is why we can't say, oh, oh, you know, this will cure you. But really, the percentage that we really tell patients, it's anywhere from 80 to 90 percent effective for those who start shots. Okay. So, you know, I'm not asking for myself, just for a friend. Like, is there any side effects from these allergy shots that I've been taking? So there is the potential for something to happen in the sense that you can get a little swelling at the site of where the injection is. Right? Because technically those are the allergens being introduced. But another potential, reaction can be what we call a systemic or anaphylactic reaction, where it's whole body reaction,

you know, from hives, trouble breathing, nausea, vomiting, swelling, which is very, very rare if it's, again, administered safely. But all of these side effects are typically mitigated because you are usually observed for a certain period of time. Yeah, they're like, Gina, you should stay here for a little while. And I had to do that four times in a row. Exactly. So there's an observation period to make sure that these reactions don't happen. And of course, wherever you are getting the allergy shots, there's usually trained staff. So if something were to happen, again, very, very rarely, we're able to administer the proper treatment to reverse it. Right. So, you know, we've been talking a lot about cats. What about food allergies? Thankfully, I'm not allergic to any food,

but are food allergens any different from the allergens we've been talking about? So yes, actually, the mechanism is the same. But the treatment is potentially different, depending on what the allergen is. So there's no allergy shots for foods. That is not yet available. Oh. But there is therapy that's called oral immunotherapy. Okay.

Where it's giving you increasing doses of the food, similar to how we talked about with allergy shots, but it's the food that you are actually getting increasing doses of orally. So some allergists practice this. This is like so interesting, right? because I remember when I was pregnant with my daughter, this was more than 15 years ago, the advice that was being given to us was like, do not expose your kids to certain foods like peanuts and eggs and even strawberries before, like, I think, one years old or something like that. And I've noticed that the guidance has basically reversed since then in favor of like early introduction. Why did that change?

Yes. So it's exactly what you're saying, which is we didn't have it right. Right? So it was like 2008-ish, 2011. Yeah, she was born in 2008. Yes. And the guidance back then was avoid the allergenic foods until age three. And we're like, okay, we're going to avoid these allergenic foods. And then my Chinese mother just gave her everything and she was like, not even one. And I was like, well, I guess she's fine.

Yes. And so after those recommendations back then, we saw this huge prevalence of peanut allergy. And we're like, what is going on here? And then there was a game-changing study in 2015. that was actually about peanut allergy and high-risk patients and babies. And they found that by introducing peanut between four to six months of age, but definitely before one year of age, it actually decreased the incidence of peanut allergy in these high-risk kids. So after then, so now for a decade, we've been telling parents and, you know, advising our pediatrician colleagues, early introduction of allergenic foods, early introduction of allergenic foods.

So my mom was right. Please don't tell her. Dr. Gina, thank you so much for talking to us today. Thank you so much for having me, Regina. If you liked this show, we have done so many episodes on allergies. We'll link those episodes in the show notes. This episode was produced by Hannah Chin. It was edited by our showrunner Rebecca Ramirez,

and the facts were checked by Tyler Jones. Cuey Lee was the audio engineer. Beth Donovan is our vice president of podcasting. I'm Regina Barber. Thank you for listening to Shorewave from NPR. Thank you.