Day of allergy immunotherapy injection

Overview

Allergy immunotherapy injection is a treatment that helps your body get used to allergens (things you are allergic to) so you have fewer or milder allergy symptoms. The injection contains a tiny amount of the substance you are allergic to, such as pollen, dust mites, or pet dander. Over time, your immune system learns to tolerate it instead of overreacting.

Allergy immunotherapy injections are a well-established treatment for moderate to severe allergies that do not improve with other treatments. They are used for hay fever (allergic rhinitis), allergic asthma, and stinging insect allergies.

Anyone with confirmed allergies that are severe or not well controlled by medications may be a candidate. It is most often recommended for people aged 5 years and older, but a healthcare provider will decide based on your specific situation.

Symptoms

Common symptoms

• Redness, swelling, or itching at the injection site
• Mild nasal congestion or sneezing shortly after the injection
• Fatigue or mild headache

Symptoms in children

• Children may have the same injection site reactions as adults.
• They might also feel anxious or scared about the needle, so reassurance and distraction during the injection can help.
• Watch for any signs of a serious allergic reaction, such as hives, trouble breathing, or dizziness.

Symptoms in older adults

• Older adults may be more sensitive to the injection and could experience more pronounced injection site reactions.
• They may also have other medical conditions or take medications that could affect the immune response, so the doctor will monitor them closely.

Causes

Main causes

• Allergy immunotherapy injection is not caused by anything—it is a treatment for allergies. The need for this treatment arises when someone has persistent, moderate-to-severe allergies that interfere with daily life and do not respond well to other medicines.

Risk factors

• Having a history of severe allergic reactions, such as anaphylaxis (a life-threatening whole-body allergic reaction).
• Having asthma that is not well controlled.
• Being allergic to multiple substances (pollen, mold, dust mites, pet dander, insect venom).

When to see a doctor

See a doctor urgently if:

• If you experience any signs of a serious allergic reaction (see emergency symptoms) after an allergy immunotherapy injection, seek immediate medical help by calling your local emergency number.
• If you have a severe injection site reaction that continues to swell or becomes infected.

Book a routine appointment if:

• Before starting allergy immunotherapy, you should see an allergist or immunologist for proper testing and to discuss if this treatment is right for you.
• Regular follow-up appointments are scheduled to monitor progress and adjust the injection dose.

Diagnosis

A healthcare provider, typically an allergist or immunologist, diagnoses allergies through a combination of your medical history, physical exam, and allergy tests.

Tests that may be done

• Skin prick test: Small drops of allergen extracts are placed on your skin and lightly pricked to see if a reaction occurs.
• Blood test (specific IgE test): Measures the level of allergy-related antibodies in your blood.

What to expect at your appointment

If tests confirm you have allergies and your symptoms are severe enough, the provider will explain how allergy immunotherapy injections work. They will discuss potential benefits and risks, and if you decide to proceed, you will start the treatment under medical supervision.

Treatment

Allergy immunotherapy injections are given in a series over several years. The goal is to reduce your sensitivity to allergens. The treatment is customized to your specific allergies.

Self-care at home

• Avoid allergens as much as possible (e.g., close windows during pollen season, use dust mite covers on bedding, wash pets after outdoor time).
• Take prescribed allergy medications as directed by your healthcare provider.
• Keep a diary of your symptoms and any reactions after injections to share with your doctor.

Medical treatments

The injections themselves are the main medical treatment. They contain a tiny amount of the purified allergen. Over the build-up phase, the amount is gradually increased until a maintenance dose is reached. This maintenance dose is then given less often, usually every 3 to 4 weeks, for 3 to 5 years. Your healthcare provider will adjust the schedule and dose as needed. Do not stop or change your injection schedule without speaking to your doctor.

When is surgery considered?

Surgery is not typically part of allergy immunotherapy. However, if you have nasal polyps or sinus disease, a surgeon may need to treat those issues separately. Allergy immunotherapy can sometimes be used after sinus surgery to help prevent regrowth or reduce inflammation.

Living with this condition

Living with allergy immunotherapy injections means making time for regular clinic visits, especially during the build-up phase. You will need to stay in the clinic for 30 minutes after each injection to be monitored. Over time, the visits become less frequent. Most people find the inconvenience worthwhile because their allergy symptoms improve significantly.

Lifestyle tips

• Plan your injection appointments so you can rest afterward if needed.
• Avoid vigorous exercise or hot showers for a few hours after the injection to reduce the risk of a reaction.
• Carry any emergency medications (like a rescue inhaler or epinephrine auto-injector) as recommended by your doctor.

Diet and exercise

No specific diet is needed for allergy immunotherapy injections. However, eating a balanced diet and exercising regularly can support your overall immune health. Avoid intense physical activity for a few hours after an injection.

Mental health and emotional wellbeing

Getting regular injections can be stressful for some people. It is normal to feel anxious about the needle or the possibility of a reaction. Talk to your healthcare team about your concerns—they can offer support and ways to make the experience more comfortable. Remember that the treatment is intended to help you feel better and reduce your allergy burden in the long run.

Prevention

You cannot prevent the need for allergy immunotherapy if you already have moderate-to-severe allergies. However, starting treatment early may help prevent allergies from getting worse or developing asthma. The treatment itself is a form of prevention—it trains your immune system to react less severely to allergens.

Vaccines

There are no vaccines for allergies. Allergy immunotherapy injections are different from vaccines; they are a treatment that exposes you to small amounts of allergens to desensitize your immune system. Tell your healthcare provider about any other vaccines you receive so they can be timed appropriately.

Screening programmes

There is no routine screening for allergies. If you have ongoing symptoms like sneezing, runny nose, watery eyes, or asthma that is triggered by certain things, see a healthcare provider for evaluation. They may recommend allergy testing to identify your triggers.

Complications

If left untreated

• If severe allergies are left untreated, they can lead to chronic sinus infections, poor sleep, and reduced quality of life.
• In some people, untreated allergic asthma can worsen and lead to more frequent asthma attacks.
• There is a small risk of anaphylaxis (a severe, life-threatening allergic reaction) from the injection itself, but this is rare if you are monitored properly.

Long-term outlook

The outlook for people receiving allergy immunotherapy injections is very good. Most people experience a significant reduction in their allergy symptoms, often for years after the treatment ends. Even if symptoms return later, the severity is usually much less. With proper medical supervision, the treatment is safe and effective.

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