What is allergy immunotherapy?

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Allergy immunotherapy works naturally with your body. Little by little, through controlled repeated doses of your allergy trigger, it teaches your over-sensitive immune system not to react. This stops or greatly reduces your allergy symptoms and can bring long-term relief.

Immunotherapy for allergies has been around for over a century but it’s still relatively unknown. In this article we’ll look at different types of allergy immunotherapy, and at some important things to consider before embarking on a course of treatment.

Allergy immunotherapy vs symptomatic medicines

Allergies, for example to pollen, dust mites, pet dander or insect stings, are caused by an overactive immune system. Your body treats an otherwise harmless substance as a threat and starts defending itself. This causes allergy symptoms that range from irritating but mild to so severe they’re potentially life-threatening.

When you have allergies the first step usually is trying to avoid the allergen triggering your symptoms. When you can’t, allergy medicines such as antihistamines and corticosteroids may help temporarily ease your stuffy or runny nose, sneezing and watery or itchy eyes.

Allergy immunotherapy goes further than temporarily relieving symptoms. It targets the underlying allergy, not your symptoms, and reprograms your immune system not to see the substance as a threat anymore. Immunotherapy for allergy is the only treatment that can change the course of the disease.

Did you Know...?

  • Allergy immunotherapy sounds new and high-tech but the first trial predated the discovery of allergy medicines such as antihistamine by 20 years.
  • It was in 1911 that British doctor Leonard Noon injected pollen extract under the skin of patients with hay fever – and found that grass no longer irritated their eyes as much.
  • Over a century later, the treatment has been studied, developed and standardized.
  • It can be given as injections or as tablets that dissolve under your tongue.
  • In January 2020, the FDA approved the very first treatment for a food allergy – peanut allergy immunotherapy for kids.
  • And it’s not only for humans. Even pets with respiratory allergies can get immunotherapy.

Life after immunotherapy for allergy

With allergy immunotherapy the goal is that your trigger isn’t a trigger anymore. It’s that simple. Many studies have shown people have fewer symptoms and need less allergy medication after immunotherapy for allergy.

You might already notice improvements in the first months of treatment but depending on the form of allergy immunotherapy it could also take 12 months. The experience after stopping allergy immunotherapy can vary too; symptoms return for some people while many find relief lasts for years. No more sneezing when you do meet pollen, dust mites or pet dander in ordinary everyday life, or not nearly as much.

Also, allergy immunotherapy may reduce the chances of getting new allergies. And it could help you avoid developing more serious symptoms.


With allergy immunotherapy the goal is that your trigger isn’t a trigger anymore. It’s that simple.

Who can benefit from allergy immunotherapy?

Allergy immunotherapy could be for you if you’re dealing with symptoms such as a stuffy, runny nose and itchy, watery eyes caused by certain allergies and you have trouble keeping your allergies under control.

Maybe you’ve tried to avoid your triggers unsuccessfully or can’t keep your allergies in check with symptomatic allergy medication. Or for some reason you may wish to cut down your long-term use of allergy meds. In these cases allergy immunotherapy could be an option.

However, allergy immunotherapy won’t be right for everyone; for instance, if you have other serious illnesses such as cardiac disease or are taking medication that would make treatment for anaphylaxis difficult. You must also have good enough lung function.

Your health care provider will be able to determine if allergy immunotherapy is for you.

Can children have allergy immunotherapy?

Some forms of allergy immunotherapy are suitable for children – but not usually for those younger than 5 years.

Allergy immunotherapy can reduce an allergic child’s symptoms and the need for allergy medication. It could also prevent them developing more allergies and progressing from milder to more severe symptoms or conditions. All this can make allergy immunotherapy valuable for controlling allergies in childhood.

Which allergies does allergy immunotherapy treat?

Immunotherapy is available for allergies to:

  • Tree pollen
  • Grass pollen
  • Weed pollen
  • House dust mites
  • Cats and dogs
  • Bee and wasp stings

When you’re allergic to any of these substances, your immune system produces immunoglobulin E (IgE) antibodies specific to your triggers.

Before starting immunotherapy your health care provider or allergist will give you a skin prick test or an allergy blood test to look for these antibodies. That way they’ll be able to identify the allergens you react to.

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Allergy immunotherapy: Types of treatment

Rather than avoiding the allergen, as you normally would, exposure is the treatment.

Allergy immunotherapy is made of the very substance you’re allergic to. It’s basically a standardized extract of certain pollen types, for example, or pet dander, even dust mites.

Small doses given regularly desensitize your immune system. Over time your body learns to tolerate the allergen instead of seeing it as a threat.

There are two types of allergy immunotherapy. Subcutaneous (SCIT) is the original method of injections just under the skin. These are often called allergy shots. The newest form of treatment is sublingual immunotherapy (SLIT), given as a fast-dissolving tablet under the tongue. SLIT-tablets are FDA approved.


Typically, people spend over 10 years trying to manage symptoms before allergy immunotherapy. Don’t wait that long if you don’t have to.

Immunotherapy allergy shots

With immunotherapy allergy shots (SCIT) the treatment happens at your doctor’s office where you’re given the injections and are monitored for any side effects. There are two phases: the build-up phase and the maintenance phase.

The build-up phase is the most time-intensive part of the process. It involves gradually increasing the amount of allergen until you’ve reached the desired dose, commonly referred to as the maintenance dose. The build-up phase in a traditional dosing regimen usually means injections once or twice a week, and typically takes 6 to 12 months. There are also “rush” or “cluster” regimens that reach the maintenance dose faster.

During the maintenance phase, it might then be two to eight weeks between injections.

Your health care provider will regularly check the progress of the treatment and decide when it makes sense to stop injections. Usually, the full course lasts for three to five years.

Allergy immunotherapy tablets

Convenience of at-home treatment is the big advantage of allergy immunotherapy tablets (SLIT) – as well as avoiding injections.

There are four FDA-approved options available in the US so far: two types of tablets for grass allergies, one tablet for short ragweed, and one for dust mite allergy.

A course of allergy immunotherapy tablets starts at the doctor’s office. The first time you’ll be monitored for any side effects. After that you can take your daily dose at home with an epinephrine pen closely at hand to be safe.

There will be regular check-ups and your health care provider will decide on the length of the treatment. It usually lasts about three to five years.

A young woman with multiple allergies

Many things making
you sneeze?

Allergy Immunotherapy for multiple allergies

Do you have multiple triggers? Over half of all people with allergies react to more than one potential allergen. How does this affect allergy immunotherapy?

Some allergy immunotherapy routines will target many triggers at the same time. Others are effective by treating the one causing the most trouble. For example, scientists have discovered that immunotherapy for house dust mite allergy can help people who also react to pollen, reducing symptoms all year round, particularly during pollen season.

Allergy immunotherapy can also take advantage of cross-reactivity between allergens. This is when substances with a similar molecular structure to your trigger can give you a reaction. Basically, allergy immunotherapy may treat one allergen and at the same time reduce the symptoms caused by any cross-reactive allergens. For example, studies have shown that allergy immunotherapy with the pollen from one species of grass is effective in treating people sensitized to other related species.  

Allergy immunotherapy: the side effects

All forms of immunotherapy can have side effects. These vary depending on the type of treatment. Local reactions aren’t serious and don’t need treatment. They also tend to happen at the start of allergy immunotherapy and less often after a couple of weeks. Try to think of it as a sign that allergy immunotherapy is working; after all, the point is to challenge your immune system. But always tell your health care provider.

There can also be systemic side effects, which means they impact on your whole body. We’ll explain about local and systemic side effects in detail below.

Local side effects of allergy shots

The most common side effects of subcutaneous allergy immunotherapy happen around where you have the injection. The skin might become red or swollen. Mostly this will clear up on its own. But an antihistamine or corticosteroid cream may help calm the skin reactions in some cases.

Local side effects of allergy immunotherapy tablets

With sublingual allergy immunotherapy it’s your mouth that may be affected, as you’d expect. Local side effects usually last around 30 to 60 minutes and could include: an itchy mouth, tongue or ears; an irritated throat; or swelling of the lips. These reactions usually do not require any treatment but an antihistamine may help if needed.

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Young woman considering allergy testing

Systemic side effects of allergy immunotherapy

Allergy immunotherapy can cause anaphylaxis. This is an allergic reaction that affects the whole body and can be serious or even life-threatening. It doesn’t happen very often: about once in every 33,300 injections and in every 100 million doses of allergy immunotherapy tablets under the tongue. There have been rare reports of fatal systemic side effects with allergy shots but none with sublingual tablets.

Most serious reactions to allergy immunotherapy occur in the first 30 minutes. So you’ll be asked to stay for at least 30 minutes at the doctor’s office after an injection and the first time you are given a sublingual tablet.

For the same reason, your health care provider will prescribe an epinephrine pen with sublingual allergy immunotherapy. Then you’re prepared when taking your dose at home.

Allergy immunotherapy = a big commitment

Immunotherapy for allergy can be a turning point for your allergy but desensitizing your body means sticking to very regular treatment for several years.

Symptoms can start to improve quite soon but you must continue your allergy immunotherapy despite feeling better. Otherwise, all the work you’ve been doing to desensitize your body could be wasted and your immune system could relapse soon after.

In short, allergy immunotherapy is a long game but with the promise of a long-term win.

Make an appointment with your allergist

So, if you struggle keeping your symptoms under control, allergy immunotherapy may be worth a conversation with your health care provider. They’ll be able to tell you which allergy immunotherapy, if any, is right for you and help you through the whole process.

Typically, people spend over 10 years trying to manage symptoms conventionally before undergoing allergy immunotherapy treatment. Don’t wait that long if you don’t have to.

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