How do allergy shots work?
An allergy shot contains a very small amount of the substance that you are allergic to (called the allergen). Common allergens include mold and pollen from grasses, ragweed and trees. So, for example, if you are allergic to grass pollen, a small amount of grass pollen will be put into the shot.
Allergy shots help your body fight the allergen. When you get shots that contain the allergen, your body’s immune system makes antibodies to the allergen. The next time you have contact with the allergen, these antibodies help block its effect. Because the antibodies block the way your body reacts to the allergen, your allergy symptoms become less severe. After many allergy shots, you might start to get relief from your allergy symptoms. This relief will last for a long time.
What kind of allergies can be treated with allergy shots?
Allergy shots work well for pollen allergies, eye allergies, bee-sting allergies and some drug allergies. In some people, allergy shots can improve asthma symptoms.
Usually people get allergy shots after they have tried other treatments that haven’t worked. Other treatments include avoiding allergens and taking medicine, such as an antihistamine.
Can everyone get allergy shots?
No. Allergy shots may not be good for you if you have severe asthma or heart problems. You shouldn’t get allergy shots if you take a beta blocker for heart problems. Children younger than 5 years of age also shouldn’t get allergy shots.
You shouldn’t start allergy shots if you are pregnant. If you have been taking allergy shots for some time and become pregnant, talk to your doctor. You may be able to continue taking your allergy shots.
What will happen if my doctor and I choose allergy shots to treat my allergy?
Your doctor will want to do an allergy test to help determine exactly what is causing your allergy. An allergy skin test puts tiny amounts of allergens onto your skin to see which ones you react to. Or, your doctor may decide to do a blood test, such as the radioallergosorbent test (called RAST) or the ImmunoCap test.
How many shots will I have to get?
Quite a few. You will start getting shots 1 or 2 times each week. After about 6 months of weekly shots, your doctor will decide when you can start maintenance treatment. Maintenance shots are usually given just once each month, year round. You’ll probably need to get maintenance shots for 3 to 5 years. Then you may be able to stop having shots.
Are allergy shots harmful?
Allergy shots are usually safe. But because allergy shots contain small amounts of an allergen you might have an allergic reaction to the shot itself. One common reaction to allergy shots is swelling at the place where the shot is given.
Some people can also have severe, shock-like reactions to an allergy shot. This type of reaction is called anaphylaxis. Anaphylaxis is rare but very serious. If you get your shots on schedule (every week or every month), you’re less likely to have this kind of reaction.
In case you have a bad reaction, your doctor will have you stay at the office for about 20 minutes every time you get your shot. That way, if you have a reaction to the shot, your doctor can give you something right away to stop it.
How long after I start taking the allergy shots before I feel better?
It usually takes 6 months or more of shots before you start feeling better and notice relief of your allergy symptoms. If you don’t feel better after this time, you should probably talk with your doctor about another kind of treatment for your allergies.
- Use of Immunotherapy in a Primary Care Office by T Craig, D.O., AM Sawyer, R.N., M.SC.N. and JA Fornadley, M.D.( 04/15/98)
Copyright © American Academy of Family Physicians
This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.