Allergy Shots: Side Effects, Efficacy, Cost, and What to Expect

Allergy shots, also known as allergen immunotherapy, consist of a series of treatments aimed to provide long-term relief of severe allergies.

You might consider allergen immunotherapy if you have severe allergy symptoms that interfere with your daily life even after you’ve made changes to your immediate environment. These shots may be used to treat allergies due to:

• dust mites
• feathers
• mold
• pet dander
• pollen
• stinging insects

When taken in the recommended succession, allergy shots can provide significant symptom relief. At the same time, this treatment option requires a long-term commitment to work effectively. Talk to your doctor about all the requirements for allergy shots and whether the shots are a good option for you.

You need to be able to commit time to this treatment method. It requires frequent injections at your doctor’s office. Allergy shots may be used by people who have:

• allergic asthma
• allergic rhinitis
• eye allergies, or recurring conjunctivitis
• insect allergies, particularly bees and other stinging insects

You may be a good candidate if you experience severe allergy symptoms year-round and you don’t want to take medications over a long period of time. This treatment method tends to work best for people who are sensitive to inhaled allergens and insect venoms.

Allergy shots are used only in people who are at least 5 years old. That’s because children younger than 5 years may not be able to fully communicate potential side effects and discomfort that would warrant stopping treatment. Allergy shots also aren’t recommended if you are pregnant or have heart disease or severe asthma.

Allergy shots work by decreasing symptoms from particular allergens.

Each injection contains small amounts of the allergen so that your body builds up immunity to it over time. The process works much like taking a vaccine, where your body creates new antibodies to combat the invasive substances. Allergy shots also improve the way other immune system cells and substances function in response to allergens. Eventually, successful immunotherapy helps the body fight off allergens and reduce adverse symptoms.

Allergy shots aim to decrease overall allergy symptoms over time. Decreased asthma symptoms are also possible if you have allergic asthma.

Before you start immunotherapy, you’ll need a full evaluation to test for allergies. Your doctor needs to know exactly which substances to use in the shots. For example, if you have allergies during pollen season, they’ll test for which types of pollen cause your symptoms. Ragweed and various tree pollens are common culprits.

Allergy testing usually consists of skin pricking. During this test, your doctor will prick the skin on your back or forearm with several types of allergens to determine which ones cause reactions.

All testing and treatment with allergy shots is conducted by a specialty doctor called an allergist or an immunologist.

Learn more: Should I get a RAST test or a skin prick test? »

Once your doctor has identified your allergens, you’ll start receiving allergy shots. The process is broken down into two phases: buildup and maintenance.

The buildup phase requires the largest time commitment. You receive injections up to twice per week to help your body get used to the allergens. This phase lasts up to six months.

The maintenance phase consists of shots administered once or twice per month. You enter this phase once your doctor determines that your body has grown accustomed to the injections. They base this decision on your reaction to the shots. The maintenance phase lasts between 3 and 5 years. It’s important that you don’t skip any of your injections if possible. Doing so can disrupt the treatment course.

You’ll need to stay at your doctor’s office for 30 minutes after each injection to monitor any side effects and reactions.

Allergy shots can provide long-term relief well after the injections have stopped. Some people who have used allergen immunotherapy may no longer need medication for their allergies. You may even notice some benefits early on in the maintenance phase of treatment.

In some cases, allergy shots don’t work. This may be due to a variety of reasons, including:

• stopping treatment due to reactions
• continued exposure to allergens at extremely high levels
• not enough allergen in the actual shots
• missed allergens during your initial evaluation

Common side effects include reactions that look like hives or mosquito bites at the site of the injection. The area can also swell to a larger bump and increase in redness. This type of reaction is normal and can last for several hours before going away without any treatment. You can help reduce swelling by applying ice to the injection site.

Some people experience allergy symptoms after their shots as a reaction to the allergens being injected. These include nasal congestion, sneezing, and itchy skin. Taking an antihistamine can help ease these symptoms.

In rare cases, allergy shots may cause a severe reaction called anaphylaxis. During anaphylactic shock, you may experience dizziness and breathing difficulties. This reaction can develop within 30 minutes of receiving an allergy shot. Your doctor will likely ask you to stay at the office for a half hour after the injection so that they can monitor you for this type of reaction.

If you’re sick, let your doctor know. You may need to skip an injection until you’ve recovered. Taking an allergy shot while you have a respiratory illness, for example, could increase your risk of side effects.

Allergy shots are typically covered by insurance. You may have to pay a copay for each visit. Copays are usually nominal fees.

If you don’t have health insurance, or if allergy shots aren’t covered under your plan, you may end up paying over $1,000 per year. Discuss payment options and costs with the doctor before beginning any treatment. Remember that allergy shots are a long-term commitment. They require many injections, so you’ll want to plan accordingly if you’re paying out of pocket.

Also consider that allergy shots could save you money on sick visits and over-the-counter allergy medications over time.

Many people respond well to allergy shots, and they can provide a source of freedom from severe allergies. It can take up to a year of maintenance shots before you see results. If you don’t see any improvements after a year, you may need to talk to your allergist about other options for allergy control.

If you have food allergies, talk to your doctor about ways you can avoid the foods you’re allergic to. Allergy shots aren’t effective in food allergy treatment.

Read more: The difference between food allergy and food sensitivity »