Allergy shots (immunotherapy) are a treatment in which 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, which means you may have fewer symptoms.
Allergy shots are given after careful skin testing for an allergy. During initial treatment, allergy shots are given once or twice a week.
This information is for people with asthma. For complete information on allergy shots, see the topic Allergic Rhinitis.
You receive allergy shots in your doctor's office. You will stay in the office for 30 minutes after getting an allergy shot to be watched for possible life-threatening reactions (anaphylaxis) to the injected allergens.
Redness and warmth at the shot sites are common and go away after a short period of time.
Allergy shots may be used to help treat asthma if:2
Allergy shots may be effective in treating asthma that is caused by an allergen and can reduce asthma symptoms and medicine requirements.3
Allergy shots are safe if the shots are given correctly. Redness and warmth at the shot site are common. Overall body (systemic) reactions such as hives, asthma symptoms, and low blood pressure are not common. But people who have asthma may be at increased risk for a severe reaction (anaphylaxis) to the shots and, possibly, death. You should have your asthma well controlled before receiving allergy shots.
Because of the possibility of anaphylaxis, the shots are given in a doctor's office where emergency care can be provided if needed. Most reactions to allergy shots occur within 30 minutes after the injection. You should stay at your doctor's office for at least this amount of time.
You must report any delayed reaction to an allergy shot. Late reactions can happen any time within 24 hours after a shot. Reactions may be local (such as a large, red or raised area around the site) or overall body reactions (such as trouble breathing).
Allergy shots should not be used when you:
The possibility of giving doses of allergens under the tongue (sublingual) instead of by injection is being studied.
- Joint Task Force on Practice Parameters (2003). Allergen immunotherapy: A practice parameter. Annals of Allergy, Asthma, and Immunology, 90(1, Suppl 1): S1–S40.
- 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.
Last Revised: May 11, 2012
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