Allergy shots are a type of immunotherapy treatment. Small doses of substances to which you are allergic (allergens) are injected under your skin. Over time, your body may become less responsive to the allergens. This means that you may have fewer symptoms.
Allergy shots are given after careful skin testing for an allergy. When you start treatment, the shots are given once or twice a week. How often you get the shots gradually decreases.
What To Expect
Allergy shots are usually given in a doctor's office. It is normal to stay in the doctor's office for a short time after getting an allergy shot to be watched for possible serious reactions to the injected insect venom.
Redness and warmth at the shot site are common. But they'll go away after a short time.
Why It Is Done
Allergy shots may be used to help treat asthma if:footnote 1
- It is clear that you have asthma symptoms when exposed to an unavoidable allergen (allergic asthma).
- Symptoms occur all year long or during a large part of the year.
- It is hard to control symptoms with medicine alone because medicines have not prevented symptoms, you've needed several medicines, or you do not want to take the medicine indefinitely.
How Well It Works
Allergy shots may be effective in treating asthma that is caused by an allergen and can reduce asthma symptoms and medicine requirements.footnote 2
- The shots reduce symptoms in people allergic to pollens, animal dander, dust mites, mold, and cockroaches.footnote 3
- Experts do not know how long allergy shots work after you stop getting the shots.footnote 3
- How much you benefit from allergy shots compared to other asthma treatment is not clear. Allergy shots may be as effective as using an inhaled corticosteroid.footnote 2
Allergy shots are safe if the shots are given correctly. The most common side effects are redness and warmth at the shot site. Some people may have reactions near where they had the shot, such as itching, hives, or swelling of the skin. More serious but less common side effects include symptoms that affect other parts of the body. Examples are hives, itching, and trouble breathing.
In rare cases, a person may have a severe allergic reaction (anaphylaxis) to the shots. Because of this possibility, the shots are given in a doctor's office or other setting where emergency care can be provided if needed. You must report any delayed reaction that you have to a shot. Late reactions can happen anytime within 24 hours after a shot.
Allergy shots may not be right for you if you:
- Have another condition, such as asthma. You may be more likely to have a severe reaction to the shots. You should have your asthma well controlled before you get allergy shots.
- Have an autoimmune disease, such as lupus.
- Are taking beta-blockers, such as propranolol (Inderal, for example). They are often used to treat heart conditions, glaucoma, migraine headaches, and high blood pressure.
- Are taking ACE inhibitors, such as captopril (Capoten, for example) or lisinopril (Prinivil, Zestril, or Zestoretic, for example). These are often prescribed for high blood pressure and a variety of heart conditions. Talk to your doctor first about the potential risks of allergy shots.
- Are not able to communicate about reactions to shots. Most doctors don't give allergy shots to children younger than age 5.
- National Institutes of Health (2007). National Asthma Education and Prevention Program Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma (NIH Publication No. 08–5846). Available online: http://www.nhlbi.nih.gov/guidelines/asthma/index.htm.
- Abramson MJ, et al. (2010). Injection allergen immunotherapy for asthma. Cochrane Database of Systematic Reviews (8). Oxford: Update Software.
- Joint Task Force on Practice Parameters (2011). Allergen immunotherapy: A practice parameter third update. Journal of Allergy and Clinical Immunology, 127(1, Suppl): S1–S55.
Current as of: February 27, 2023
Author: Healthwise Staff
Medical Review:John Pope MD - Pediatrics & Adam Husney MD - Family Medicine & Elizabeth T. Russo MD - Internal Medicine