Tips to Remember:
This brochure is designed to answer the basic
who, what, when, where, how and why questions you may have regarding
allergen immunotherapy, also known as "allergy shots."
What is immunotherapy?
Allergen immunotherapy is a form of treatment aimed at decreasing your
sensitivity to substances called allergens. These allergens are identified
by allergy testing, and are the substances that trigger your allergy
symptoms when you are exposed to them. Allergen immunotherapy involves
injecting increasing amounts of an allergen to a patient over several
months. Immunotherapy has been shown to prevent the development of new
allergies and, in children, it can prevent the progression of the allergic
disease from allergic rhinitis to asthma. Allergen immunotherapy can lead to
the long-lasting relief of allergy symptoms after treatment is stopped.
Who should be treated with immunotherapy?
Immunotherapy is only recommended for allergic asthma, allergic rhinitis and
conjunctivitis, and stinging insect allergy. Immunotherapy for food
allergies is not recommended. The best option for people with food allergies
is to strictly avoid that food. The decision to begin immunotherapy will be
based on several factors including:
- Length of allergy season and severity of symptoms.
- How well medications and/or environmental controls control allergy
- Desire to avoid long-term medication use.
- Time: immunotherapy will require a significant time commitment.
- Cost: may vary depending on region and insurance coverage.
Can children receive immunotherapy?
Five is the youngest recommended age to start immunotherapy in the United
States for several reasons, including the difficulties younger children may
have in cooperating with the immunotherapy program. Recent studies have
suggested immunotherapy may prevent the development of new allergies in
children and also may prevent the development of asthma in children who have
There is no upper age limit for receiving
immunotherapy. In considering immunotherapy in older persons, consideration
must be given to the other medical conditions (such as cardiac disease) that
are more frequent in older individuals, which could potentially make
immunotherapy more risky.
Where should immunotherapy be given?
Immunotherapy should be given under the supervision of a physician in a
facility equipped with proper staff and equipment to identify and treat
adverse reactions to allergy injections. Ideally, immunotherapy should be
given in the prescribing allergist/immunologist's office but if this is not
possible, your allergist/immunologist should provide the supervising
physician with comprehensive instructions about your immunotherapy
How does immunotherapy work?
If you are allergic to a substance such as ragweed, you will not overcome
your allergy by repeatedly inhaling ragweed into your nose or lungs. So, how
can a series of injections that include the substances that trigger your
allergies, relieve your allergy symptoms?
Allergen immunotherapy works like a vaccine.
Your body responds to the injected amounts of a particular allergen, given
in gradually increasing doses, by developing an immunity or tolerance to the
As a result of these immune changes,
immunotherapy can lead to decreased, minimal or no allergy symptoms when you
are exposed to the allergen(s) included in the allergy vaccine.
There generally are two phases to
immunotherapy: a build-up phase and a maintenance phase.
- Build-up phase: involves receiving
injections with increasing amounts of the allergens. The frequency of
injections during this phase generally ranges from one to two times a
week, though more rapid build-up schedules are sometimes used. The
duration of this phase depends on the frequency of the injections but
generally ranges from three to six months.
- Maintenance phase: This phase
begins when the effective therapeutic dose is reached. The effective
maintenance dose is different for each person, depending on their level of
allergen sensitivity (how 'allergic they are' to the allergens in their
vaccine) and their response to the immunotherapy build-up phase. Once the
maintenance dose is reached, there will be longer periods of time between
immunotherapy treatments. The intervals between maintenance immunotherapy
injections generally ranges from every two to every four weeks. Your
allergist/immunologist will decide what range is best for you.
The benefits of immunotherapy, in terms of
reduced allergy symptoms, can begin during the build-up phase but may take
as long as 12 months on the maintenance dose. Improvement with immunotherapy
may be progressive throughout the immunotherapy treatment period.
Effectiveness of immunotherapy appears to be related to length of treatment
and the dose of the allergen. Failure to respond to immunotherapy may be due
to several factors including:
- Inadequate dose of allergen in the allergy vaccine.
- Missing allergens not identified during the allergy evaluation.
- High levels of allergen in environment (i.e. inadequate
- Significant exposure to non-allergic triggers (i.e. tobacco
If there is no improvement after a year of
maintenance immunotherapy, possible reasons for failure to respond should be
explored. If no apparent reason is found then discontinuation of
immunotherapy should be considered and other treatment options should be
When should immunotherapy be stopped?
If immunotherapy is successful, maintenance treatment is generally continued
for three to five years. The decision to stop immunotherapy should be
discussed with your allergist/immunologist after three to five years of
treatment. Some individuals may experience lasting remission of their
allergy symptoms but others may relapse after discontinuing immunotherapy.
Therefore, the decision to stop immunotherapy must be individualized.
What are the possible reactions?
There are two types of adverse reactions that occur with immunotherapy:
local and/or systemic reactions.
Local reactions: are fairly common and
present as redness and swelling at the injection site. This can happen
immediately, or several hours after the treatment.
Systemic reactions: are much less
common than local reactions. Systemic reactions are usually mild and respond
rapidly to medications. Symptoms can include increased allergy symptoms such
as sneezing, nasal congestion or hives. Rarely, a serious systemic reaction,
called anaphylaxis, can develop after an immunotherapy injection. In
addition to the symptoms associated with a mild systemic reaction, symptoms
of an anaphylactic reaction can include swelling in the throat, wheezing or
a sensation of tightness in the chest, nausea, dizziness or other symptoms.
Systemic reactions require immediate
treatment. Most serious systemic reactions develop within 30 minutes of the
allergy injections and this is why it is recommended you wait in the office
for 30 minutes after your allergy injections. Your allergist/immunologist is
trained to monitor for such reactions and his or her staff is trained to
identify and treat systemic reactions.
Allergy immunotherapy is a proven effective treatment for allergic rhinitis,
allergic asthma, and stinging insect allergy. It also may effective in some
individuals with atopic dermatitis (eczema) if they have allergies to
airborne allergens. Immunotherapy can potentially modify the allergic
disease leading to lasting remission of allergy symptoms. Immunotherapy may
play a preventive role in pediatric allergic disease, in terms of
development of asthma and new allergies, thus early involvement of the
allergy specialist may be important in the child with allergy symptoms.
Adverse reactions to immunotherapy are rare but do require immediate medical
attention and this is why immunotherapy should be administered in a medical
facility appropriately outfitted with equipment and staff capable of
identifying and treating these reactions.
Your allergist/immunologist can provide
you with more information on allergen immunotherapy, or "allergy shots."
Tips to Remember are created by the
Public Education Committee of the American Academy of Allergy, Asthma and
Immunology. This brochure was updated in 2003.
The content of this brochure is for
informational purposes only. It is not intended to replace evaluation by a
physician. If you have questions or medical concerns, please contact your
American Academy of Allergy,
Asthma and Immunology
555 East Wells Street
Milwaukee, WI 53202-3823
Physician Referral and
AAAAI Web site