Immunotherapy (Allergy Shots)
If you have allergies, you may be wondering if allergy shots are the best treatment
for you. After all, getting regular shots isn't anyone's idea of fun, but the possibility
of being free from your allergy symptoms may be worth it.
Allergies are the result of a chain reaction that starts in the immune system. Your
immune system controls how your body defends itself. For instance, if you have an
allergy to pollen, your immune system identifies pollen as an invader or allergen.
Your immune system overreacts by producing antibodies called Immunoglobulin E
(IgE). These antibodies travel to cells that release chemicals, causing an allergic
Immunotherapy (allergy shots) is aimed at increasing your tolerance to allergens
that trigger your symptoms every time you are exposed to them. An allergist is the
most qualified physician to test which allergy you have and tell you if allergy shots
are right for you.
Who Can Be Treated with Shots
Allergy shots are recommended for patients with allergic asthma, allergic rhinitis
(nasal/sinus allergies), and stinging insect allergy. They are not recommended for
food allergies. Before a decision is made to begin allergy shots, the following issues
must be considered:
- Length of allergy season and the severity of your symptoms
- Whether medications and/or changes to your environment can control your
- Your desire to avoid long-term medication use
Immunotherapy for children is effective and often well tolerated. It might prevent
the onset of new allergen sensitivities or the progression to asthma.
How Do Allergy Shots Work?
Allergy shots work like a vaccine. Your body responds to the injected amounts of a
particular allergen (given in gradually increasing doses) little by little, developing a
resistance and tolerance to it. Allergy shots can lead to decreased, minimal or no
allergy symptoms when you are again exposed to the allergen(s) in the shot.
There are two phases to immunotherapy: build-up and maintenance.
The build-up phase, generally ranging from six to nine months, involves receiving
injections with increasing amounts of the allergens, until a predetermined top dose
is reached. The frequency of injections is generally once a week, though more rapid
build-up schedules are sometimes used. The maintenance phase begins when the
most effective dose is reached. This dose is different for each person, depending on
how allergic you are and your response to the build-up phase. Once the
maintenance dose is reached, there are longer periods between injections, typically
When Will I Feel Better?
For many people, a decrease in symptoms is seen during the build-up phase; for
others, it may take as long as six to twelve months on the maintenance dose.
If you don't respond, it may be caused by:
- Not enough dose of the allergen in your vaccine
- Missing allergens not identified during your allergy testing
- High levels of the allergen in your environment
- Major exposure to non-allergic triggers (i.e. tobacco smoke)
If there is no improvement after a year of maintenance allergy shots, your allergist
will discuss other treatment options with you.