Allergy shots are a type of immunotherapy
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
Allergy shots are given after careful
skin testing for an allergy. During initial treatment,
allergy shots are given once or twice a week.
- At first, a small amount of allergens is used.
The amount of allergen injected is increased slightly each time, unless you
have a serious
allergic reaction. After 4 to 6 months of weekly
shots, the dose will contain an optimal amount of allergen. This is called the
- After reaching maintenance, you get the same
dose in shots every 2 to 4 weeks for another 4 to 6 months.
getting allergy shots, you need to see your doctor to be checked every 6 to 12
months. After 3 to 5 years of getting allergy shots, you and your doctor may
need to make the decision to stop allergy immunotherapy or to continue. Many
children who are helped by allergy shots stop taking them after 3 to 5 years.
But these children often continue to benefit from having received the
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
- 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.
Allergy shots may be effective in
treating asthma that is caused by an allergen and can reduce asthma symptoms
and medicine requirements.3
- The shots reduce symptoms in people allergic to
dust mites, mold, and cockroaches.1
- Experts do not know how long allergy shots work after you stop getting the shots.1
- 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.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 you receive 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 that you have to a 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).
- Children younger than 2 should not have allergy
shots. Children ages 3 to 4 may find it hard to receive many shots over a
long period of time. Talk with your doctor about whether allergy shots are
suitable for your child.
- Older adults may be taking medicines or
have other medical conditions that may increase the risk of a severe reaction
to allergy shots.
- Pregnant women who are already taking allergy
shots may continue them. But it is not recommended that allergy shots be
started during pregnancy.
- Allergy shots take 3 to 5 years to
complete and are expensive. It may take up to 1 year for allergy symptoms to
improve. During your treatment, your doctor should evaluate you at least once
every 6 to 12 months.
Allergy shots should not be used
- Have had a recent
unstable angina, or other heart conditions or are
- Are unable to communicate
(can't tell your doctor about reactions to shots). Most doctors do not give
allergy shots to children younger than 5.
If you have a weakened immune system (such as from
HIV infection) or an autoimmune disease (such as
multiple sclerosis), talk to your doctor about whether allergy shots are safe for you.
Sublingual immunotherapy may be another way to treat certain pollen allergies. Instead of getting shots, you dissolve a tablet under your tongue daily. Each tablet has a small amount of allergen in it. This treatment, like allergy shots, helps your body "get used to" the allergen, so your body reacts less to it over time. Oral and sublingual immunotherapy is being studied for other types of allergies also.
Complete the special treatment information form (PDF) (What is a PDF document?) to help you understand this treatment.
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.
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.