Everything You Need to Know About Allergy Shots

Allergies affect almost 1 in 3 people in the United States. They are a bothersome condition that can lower productivity at school and work, prevent involvement in outdoor activities, and impair overall quality of life.

Several medications are available to treat allergy symptoms, including oral antihistamines, topical antihistamines, and corticosteroids (nasal sprays). These medications are generally effective. However, up to one-third of people with allergy symptoms do not get relief from allergy medicines. Such individuals could benefit from allergy shot treatment.

Allergy shots can provide significant relief from allergy symptoms, but to work effectively, they require a long-term commitment to the treatment. Please continue reading to learn more.

How do allergy shots work?

Allergy shots are a type of immunotherapy. They consist of a series of injections given regularly over a period of 3-5 years. Each allergy shot contains tiny doses of a substance called an allergen. The specific allergen in your allergy shot is the substance that triggers your allergies. It is enough to stimulate your immune system without causing a full-blown allergic reaction. Allergy shots may contain one or more allergens.

Doctors gradually increase the dose of allergens in your allergy shots over time. This allows your body to get used to the allergens, i.e., slowly, it desensitizes your body to the allergens and helps you build tolerance. As a result, your symptoms become less severe as the treatment progresses.

What allergy symptoms can an allergy shot treat?

Allergy injections can help control symptoms of:

Seasonal allergies (allergic conjunctivitis and allergic rhinitis or hay fever symptoms) caused by pollen, trees, grasses, weeds, and ragweeds.
Year-round allergies caused by indoor allergens like dust mites, mold spores, pet dander, feathers, and cockroaches.
Stinging insect allergy caused by the stings of bees, wasps, yellow jackets, hornets, and fire ants.
Allergic asthma that is made worse by allergies.
Eczema that is made worse by dust mite allergy.

Can allergy shots treat food allergies?

No, unfortunately, there are no allergy shots available for allergies to certain foods or for urticaria (chronic hives).

Am I a good candidate for allergy shots?

You may be a good candidate for allergy shots if allergy medications don’t control your symptoms well, cause bothersome side effects, or interfere with your other medications. Allergy shots may also be a good option if you want to reduce the long-term use of allergy medicines. You can consider this treatment if you’re allergic to insect stings.

What to expect when getting allergy shots?

Before receiving allergy shots, your doctor will do a blood or skin test to find out which common allergens cause your symptoms. This allergy test involves scratching a small amount of the suspected allergen into your skin and observing for adverse symptoms like swelling and redness.

Once the allergens have been determined, you will get the shot in your doctor’s office. The injection is usually given in the upper arm. You will need to remain in your doctor’s office for 30 minutes after the injection to ensure you don’t have a reaction.

Be sure to tell your healthcare team if you have ever had adverse symptoms after an allergy shot. Also, let your healthcare providers know if you feel unwell after the treatment. This is especially important if you have asthma symptoms.

How long does allergy shot treatment last?

The treatment consists of two phases:

Build-up phase: This is the first 3-6 months when the shots are usually given 1-3 times per week. Your doctor will slowly increase the amount of allergen in each subsequent shot during the buildup phase. A faster buildup phase called rush immunotherapy may be done to provide relief from severe allergy symptoms. However, it is associated with an increased risk of severe reactions.
Maintenance phase: This phase lasts 3-5 years. The maintenance shots are usually given every 4-6 weeks.

What do I need to know before getting allergy shots?

You should know that you will need to commit to long-term treatment requiring regular visits to your doctor’s office to get your allergy shots. The allergen immunotherapy treatment usually lasts for 3-5 years.

You should also know that improvement in your allergy symptoms will not happen immediately. Your symptoms will slowly improve during the first year of treatment. However, most people notice the maximum improvement during the second allergy season after they start subcutaneous immunotherapy. By the third year, as you continue taking a maintenance dose, you can expect desensitization to the allergens. By this time, you should not have allergic reactions to the triggers.

After you successfully complete the treatment, you can expect long-term relief from allergy symptoms. Many people don’t have significant problems with allergies even after they stop taking the allergy shots. However, others need to keep taking the shots to keep their symptoms under control.

What are the long-term side effects of allergy shots?

Most people tolerate allergy shots well. However, these injections contain substances to which you are allergic so they can cause local reactions at the injection site, such as redness, swelling, and irritation. The injection site reactions typically go away in a few hours to one day.

Rarely, more serious systemic reactions can occur. This may include symptoms like hives, sneezing, nasal congestion, or more severe reactions such as throat swelling and chest tightness, which require emergency medical attention.

Anaphylaxis is a rare but potentially life-threatening reaction that can occur after allergy shots. The most serious reactions usually occur within 30 minutes of exposure to the allergen, but they can happen later on as well. You must seek treatment immediately at the nearest emergency room if you develop signs and symptoms such as trouble breathing or low blood pressure after an allergy shot.

You can lower your risk of a severe reaction by sticking to the recommended schedule of regular injections. Your healthcare provider may recommend taking an antihistamine before the allergy shot to lower your risk of a local reaction.

Why are my allergy shots not working?

Allergy shots are usually effective treatments. However, they may not work in some cases if:

Treatment is stopped too soon.
There is continued exposure to high levels of allergens.
The allergy shots don’t contain enough allergens.
The specific allergens that cause your symptoms are misidentified during the initial evaluation.
New allergies develop after treatment is started.

Are allergy shots worth the trouble?

Allergy shots can effectively treat chronic allergies when other treatments have failed. Studies show that 8-9 out of 10 people see a reduction in their symptoms after getting allergy shots. If immunotherapy is successful, you may be able to enjoy complete relief from allergies without taking medications.

However, allergy immunotherapy does have some drawbacks. It does not work for all types of allergies. For example, allergy shots are ineffective in treating food allergies or urticaria. Additionally, there is the risk of a severe reaction from exposure to the allergen. Last but not least, allergy shots require a relatively long time commitment for successful treatment.

Like with any treatment, there are advantages and disadvantages. Your healthcare provider can further overview allergy shots to help you decide if they are a good option for you.

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