What is Immunotherapy (Allergy Shots)?
Immunotherapy or allergy shots are injections given into the skin of the arm of individuals suffering from severe allergies to help reduce, prevent, or stop the symptoms of allergies over time.
An allergy is a reaction by your immune system to substances that do not cause a reaction in most other people. These substances are known as allergens. The most common allergens are pollens released by trees, grasses or weeds, dust mites, pet dander, mold spores, food, insect stings, and medicines. Allergies can cause various symptoms such as sneezing, runny nose, teary eyes, swelling, itching, rashes, coughing, wheezing, or breathlessness. Allergies can range from minor to severe. Anaphylaxis is a serious reaction which can be life-threatening.
Immunotherapy treatment involves administering gradually increasing doses of the substance, or allergen, to which the individual is allergic. The incremental doses of the allergen cause the immune system to become less sensitive to the substance, probably by causing the production of a “blocking” antibody, which reduces the symptoms of allergy when the substance is encountered in the future. Allergy shots also reduce the inflammation that characterizes asthma and rhinitis. A shot may be administered once a week (sometimes more often) for about 7 months, after which shots can be given every 2 weeks. Eventually, injections can be administered every 4 weeks. The duration of the immunotherapy may typically last around 3 to 5 years or sometimes longer.
Indications for Immunotherapy (Allergy Shots)
Immunotherapy (allergy shots) is usually indicated if you have severe allergy symptoms that interfere with your activities of daily living, despite the changes you have made to your immediate environment for the treatment of allergic conditions, such as:
- Allergic rhinitis - affecting the nose
- Allergic conjunctivitis - affecting the eyes
- Allergic otitis media - affecting the ears
- Bronchial asthma – affecting the lungs and breathing
- Severe insect sting allergy
Both adults and children can receive allergy shots, although it is not usually recommended for children under age 5. When considering allergy shots for an older adult, medical conditions, such as cardiac disease should be taken into consideration and discussed with your immunologist/allergist first.
Who is a Good Candidate for Immunotherapy (Allergy Shots)?
You may be a good candidate for allergy shots if:
- You want to decrease your long-term use of allergy medication
- Allergy medications can interact with other medications you need to take or cause troublesome side effects
- Medications are unable to manage your symptoms effectively, and you cannot avoid the things that cause your allergic reactions
- You are allergic to insect stings
Preparation for Immunotherapy (Allergy Shots)
Prior to beginning treatment, your allergist will take a complete medical history, discuss with you about your symptoms, and identify trigger factors for your allergy symptoms. Your physician will then perform skin or blood tests to confirm the specific allergens causing your symptoms and recommend suitable allergy care methods as treatments. Allergy shots are usually recommended only if the individual seems to be selectively sensitive to several allergens. While most allergies cannot be cured, treatments can help alleviate your allergy symptoms.
Getting Your Allergy Shots
You will receive your allergy shots usually in your upper arm at your provider's office. It will contain a tiny amount of substance or substances that you are allergic to such as pollen, dust mites, mold, pet dander, or bee venom. To be effective, allergy shots are administered on a schedule that involves two phases:
- Build-up phase: In this phase, you will receive injections with increased amounts of the allergens about once or twice per week. The length of this phase depends on how often the injections are received, but typically lasts from 3 to 6 months.
- Maintenance phase: This phase begins once you have reached your “effective therapeutic dose.” In this phase, you will receive your allergy injections less often, typically every 3 to 4 weeks. The maintenance phase usually lasts 3 to 5 years or sometimes longer.
You may observe a decrease in your allergy symptoms during the build-up phase, but it may take as long as 12 months on the maintenance dose to observe an improvement. If allergy shots are effective, maintenance treatment is normally continued for 3 to 5 years.
You are advised to wait in your care provider’s office for at least 30 minutes after you receive allergy shots as most serious side effects develop within 30 minutes of allergy shots.
Risks and Complications
Some of the temporary side effects associated with allergy shots include:
- Swelling and redness at the injection site
- Increased allergy symptoms such as nasal congestion, sneezing, or hives
- Anaphylactic reaction (rarely). This can include dizziness, nausea, wheezing or tightness in the chest, and swelling of the lips, throat, eyes, or face.