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 reaction.
If you suffer from allergy symptoms, you may wonder if allergy immunotherapy (allergy shots or allergy tablets) is the best treatment for you. The concept behind allergy immunotherapy, whether it is received in the form of shots or tablets, is that the immune system can be desensitized to specific allergens that trigger allergy symptoms. Although it requires time and patience, the payback can be long-term relief.
How Do Allergy Shots Work?
Allergy shots work much like a vaccine. Your body responds to injected amounts of a particular allergen given in increasing doses, eventually developing a resistance and tolerance to it. Allergy shots can lead to decreased, minimal or no allergy symptoms.
There generally are two phases: build-up and maintenance. Build-up often ranges from three to six months and involves receiving injections with increasing amounts of the allergens. The shots are typically given once or twice 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 injections. Once the maintenance dose is reached, there are longer periods between injections, typically two to four weeks.
Occasionally doctors give cortisone-type shots that can temporarily reduce allergy symptoms. These types of shots are different and should not be confused with allergy immunotherapy shots.
Who Can Be Treated with Allergy Shots?
Allergy shots may be a good treatment approach for people with allergic rhinitis (hay fever), allergic asthma, conjunctivitis (eye allergy) or stinging insect allergy. Allergy shots are not recommended for food allergies.
Allergy shots for children age five and older are effective and often well tolerated. They might prevent the onset of new allergen sensitivities or the progression to asthma.
Allergy shots are not started on patients who are pregnant but can be continued on patients who become pregnant while receiving them. In some patients with other medical conditions or who take certain common medications, allergy shots may be of risk. It is important to mention other medications you talk to your allergist.