An allergic reaction is an overreaction of the immune system to a substance called an allergen. Allergens include chemicals, foods, medicines, mold, plants, and pollen.

Symptoms of an allergic reaction can range from mild and annoying to severe and life threatening.

  • Allergens can affect any tissue in the body, such as the airway, eyes, gastrointestinal tract, nose, lungs, and skin.
  • Some allergic reactions, such as hives or itching around an insect bite or where a plant or chemical touched the skin, affect only one area of the body.
  • Other allergic reactions may affect the entire body, causing itching, swelling, or difficulty breathing.
  • A severe allergic reaction (called anaphylaxis) can lead to shock and even death. Allergic reactions do not occur the first time a person is exposed to an allergen. A person may become more sensitive to the allergen with each exposure.


Treatment of allergies may consist of various medications and environmental control. If this is not successful then skin testing may be done to determine the specific allergen causing the symptoms. Immunotherapy (allergy injections) may be considered. In our office we do allergy testing on individuals 12 years and older. Younger children may be referred to a pediatric allergist.


You must first have skin testing to find out which allergen you are allergic to.

When you get allergy shots (immunotherapy), your allergist or doctor injects small doses of substances that you are allergic to (allergens) under your skin. This helps your body “get used to” the allergen, which can result in fewer or less severe symptoms of allergic rhinitis. At first, the shot is given once or twice a week. You gradually receive more of the allergen in each injection. After about 4 to 6 months of weekly shots, you are usually getting the proper amount of allergen in the shot. This is called the maintenance dose. The period between shots is gradually increased to about a month. And the dose usually stays the same each month. After 1 year of maintenance, your allergist will check to see if you have fewer or less severe symptoms. If your allergy symptoms have not changed, you will no longer get the shots. If your symptoms have improved, you may continue to get monthly shots for up to 3 to 5 years.

What To Expect From Immunotherapy

In the beginning you receive allergy shots in your allergist’s office. You will stay in the office for 20 to 30 minutes in the beginning, after you receive the injection, in case you have a severe reaction (anaphylaxis) to the injected allergens. Although severe allergic reactions are very rare, all patients who undergo allergy injections in our office will be prescribed an epinephrine injector to be used if a severe reaction occurs while not in a clinic setting. Redness and warmth at the shot site are common, but they go away after a short period of time. After the maintenance dose is reached you may have the option of taking the serum home or to a clinic near you to continue the injections.

Why It Is Done

Allergy injections can reduce your reaction to allergens, which can result in fewer or less severe symptoms. They may also prevent children who have allergic rhinitis from getting asthma. Recommendations on when to get allergy shots vary, but in general you and your doctor may consider them when allergy symptoms are severe enough that the benefit from the shots outweighs the expense and commitment to treatment..

  • You are allergic to substances that are hard to avoid
  • Avoiding allergens and using medication do not control symptoms, or you have to take medicine all the time to control symptoms
  • Side effects of medicines are a problem.
  • You want a treatment for the cause of your allergy, rather than treatment for just the symptoms
  • You have another condition that is being affected by allergic rhinitis, such as asthma
  • You want to lower the chance that you will develop asthma.

How Well It Works

Allergy shots are effective in treating allergic rhinitis and allergic asthma. The shots reduce symptoms in those allergic to pollens, animal dander, dust mites, mold, and cockroaches. Experts do not know how long allergy shots are effective after you stop getting the shots. For allergies to some grasses, shots have been effective for 3 to 4 years.

Allergy shots have resulted in :

  • Dust mite allergies being about 3 times better than before treatment
  • Pollen, mold, or animal dander allergies being about 4 times better than before treatment. Although you still need to avoid allergens, you may be able to use less medicine or stop using medicines.

What To Think About

Although expensive, allergy shots may cost no more than the combined cost of medicine, doctor and emergency room visits, and missed days of school or work over several years. Most insurance companies cover most if not all the cost of allergy testing and treatment. But you may need to take regular shots for 3 to 5 years. During your treatment, you should see your doctor at least once every 6 months to review the effectiveness of the immunotherapy the expense and the time spent getting the shots.

Allergy shots treat an allergy to just one allergen or group of them. The allergens can usually be combined into one or two shots. If you or your child has another condition, such as asthma, you may be more likely to have a severe reaction to the shots. You should have your asthma well controlled before you get allergy shots.

Some medicines or other medical conditions may increase the risk of a severe reaction to allergy shots.

You must report any delayed reaction to an allergy shot. Late reactions can happen any time within 24 hours after a shot. Reactions may just affect the injection site (such as a large, red or raised area around the site) or they may affect your overall body (such as trouble breathing).

Pregnant women who are already taking allergy shots may continue them. But do not start taking them during pregnancy.

Allergy shots should not be given if you:

  • Have had a recent heart attack, unstable angina, or other heart problems or are taking beta-blockers.
  • 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.
  • Have an immune system disease (such as AIDS).