Everything You Need to Know About Allergy Shots

Once yellow pollen begins to coat car windshields and weeds start to grow out of cracks in the sidewalk, the 50 million allergy suffers in the United States know it's time to break out their bottle of Benadryl and mentally prep themselves for the itchy, watery eyes and stuffy, red-blown nose that will become their ~lewk~ for the spring or summer season. (Speaking of, here's how to deal with summer allergies, specifically.)

Thankfully, though, there is a workaround for those who are fed up with their seasonal allergies and don't want to deal with their unbearable symptoms any longer: Allergy shots. Here, an immunologist gives the low-down on the allergy treatment method, including its benefits, side effects, and efficacy.

What Are Allergy Shots?

In order to better understand how allergy shots work, you need to know why allergies happen in the first place. Generally, allergies occur when you're exposed to a typically harmless foreign substance (think: pollen, dust mites, animal dander) and your immune system mistakenly identifies it as a threat. In response, your body will release certain chemicals, called histamines, that can cause sneezing, runny nose, congestion, and/or red, watery, or itchy eyes, according to the Centers for Disease Control and Prevention. You may also develop a cough, hives, rashes, a scratchy throat, and, in severe cases, breathing trouble and asthma attacks, according to the Asthma and Allergy Foundation of America.

The problem: There isn't a cure for allergies, and the allergy and asthma medications available today control — but not prevent — the symptoms, says Purvi Parikh, M.D., an adult and pediatric allergist and immunologist with Allergy & Asthma Network. Allergy shots, however, are currently the most effective method of alleviating your symptoms for good. "They're the closest thing we have to achieving a cure," says Dr. Parikh. "It's the best underlying treatment."

You can think of allergy shots, also called subcutaneous immunotherapy, like a vaccine, according to the American Academy of Allergy, Asthma & Immunology. Your allergist will inject you with tiny, diluted doses of your allergen, gradually increasing the amount over the course of six months, to help your body develop a tolerance to the allergen — and ease up or stop those reactions altogether, says Dr. Parikh. "As a result, not only do people's eyes and nose get better, but I've seen people's asthma virtually go away," she explains.

Allergy shots are commonly used to combat airborne allergens, such as pollen, dust mites, mold, and animal dander, says Dr. Parikh. Occasionally, allergists will use the technique to treat medication allergies; for example, a cancer patient who became allergic to their chemotherapy could be desensitized to it via allergy shots in order to continue their treatment, she explains. Unfortunately for those with food allergies, "we don't have this type of desensitization available for foods yet," she says. "The FDA did just approve something similar for peanuts [a powder that's mixed with food], but it's still all very new and experimental."

Who Should Get Allergy Shots?

While Dr. Parikh says she recommends allergy shots for most of her patients who suffer from allergies, there are a few key characteristics that make you a strong contender. People who don't respond to over-the-counter symptom relief treatments or whose allergies get worse with every passing season may benefit most from the shots, she says. Allergy shots may also be a good idea if you're unlucky enough to have allergies year-round (say, a pollen allergy in the spring, summer, and fall, or an allergy to your own pet's dander), she adds. Likewise, those who suffer from the "atopic triad" — having allergies, asthma, and eczema — are typically ideal candidates for the shots, says Dr. Parikh.

There aren't too many cases in which it's not recommended to start an allergy shot treatment, and Dr. Parikh says she has even safely given them to children and elderly folks. Still, the American Academy of Allergy, Asthma & Immunology states that allergy shots aren't typically used on children younger than five years old, as they might struggle to stick with the program or express any discomfort they may be experiencing. Folks of all ages who are dealing with uncontrolled asthma (think: they just had an attack that landed them in the hospital) would likely need to wait until their condition has become stable before starting allergy shots, as they'd be at a greater risk of having a severe allergic reaction, says Dr. Parikh.

The U.S. National Library of Medicine also notes that those who take ACE inhibitors or beta-blockers (which both help to lower blood pressure) or have heart conditions may not be ideal contenders for allergy shots. These medications are linked with a greater risk for anaphylaxis — a life-threatening reaction that, although rare, can occur after receiving allergy shots. Likewise, pregnant women typically aren't recommended to receive an allergy shot treatment unless they started it before they became pregnant, according to the NLM. The reason: Any reactions could potentially harm the baby, and doctors don't always know exactly how allergy-shot newbies will respond to the treatment, per the Cleveland Clinic. However, doctors will know how their established patients typically react to treatment, so newly pregnant folks can continue to receive their allergy shots at the same dose (rather than a gradually increased one) until after delivery, according to the American Academy of Allergy, Asthma & Immunology.

In any case, talk to your allergist if you're considering starting an allergy shot regimen to soothe your sniffles or itchy eyes, no matter the catalyst of the irritating symptoms.

What to Expect When Getting Allergy Shots

After you and your allergist have decided that allergy shots are the best course of action for you, you'll first have to get an allergy test to confirm that you are, in fact, dealing with an allergy and to which substances, says Dr. Parikh. "When we make the shots, we do it to target your specific allergens, so my allergy shots might look different from yours if we're both allergic to different things," she explains.

For the first six months of treatment, you'll drop by your allergist's office for a weekly shot, says Dr. Parikh. Throughout this "build-up phase," your doc will slowly up the dose of the allergen to gradually boost your tolerance to it, she explains. After that, you'll get your shot once monthly for three to five years, known as the "maintenance phase." "The whole point is that you're trying to change your immune system so your allergies don't come back — that's why you need to be on them for so long," says Dr. Parikh.

Receiving an injection of your allergen does mean there is a risk of an allergic reaction, but a severe one is rare, occurring in less than 1 percent of people, says Dr. Parikh. Most often, you'll develop a "mosquito bite-like" bump, with redness or swelling, or itching at the injection site, she says. Regardless of how you initially react, your allergist will have you wait in the office for 30 minutes after each shot just in case you do develop a more severe reaction that requires medical attention, she explains.

With such a long-term commitment, it's inevitable that you'll miss an appointment or two at some point, whether it be due to a vacation or a pandemic. In most instances, though, it's NBD, says Dr. Parikh. "We have up to three weeks [after the missed dose] where we can still advance you [to a higher dose]," she explains. "But if you miss a larger gap, then we just adjust — we have to cut your dose back a little bit and then go from there." In that case, you are prolonging your treatment slightly, but if you skip your allergy shots for longer than six months, you'll have to go back to square one, she says.

Do Allergy Shots Work?

TL;DR: Allergy shots aren't a quick fix for your irritating symptoms, but there "you feel much better even in the first six months," says Dr. Parikh. "It's not like you need to wait three to five years to feel better — you'll probably feel better by the next allergy season. It's just that you have to be on it for that long so your allergies don't come back."

Remember, allergy shots aren't a full-fledged cure, so there is still a chance you experience some unpleasant symptoms after the treatment period, though they tend to be much milder, says Dr. Parikh. Based on her experience, Dr. Parikh says about one-third of patients who complete their allergy shot treatment don't have adverse reactions to their allergens for the rest of their lives, while another third are allergy-free for a few decades before developing some symptoms. "Then there are the unlucky few who need the shots even after they go off, and they have to come back to continue that maintenance dose," she says. "It varies person to person, but the majority of people after [the maintenance period] don't need to keep taking allergy shots indefinitely."

And if getting a handful of needle pokes is what it takes to put an end to your coughing fits, itchy eyes, and midday, snooze-inducing Benadryl doses, it's well-worth giving allergy shots a shot.