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Allergy Shots – What You Need to Know

Allergy Shots

Allergen immunotherapy injections or “allergy shots” are a treatment for patients with allergic runny or stuffy nose, allergic asthma or life threatening reactions to insect stings. Allergy shots are for people who have serious allergy symptoms that are not helped by changes to their environment and/or medicines. Some studies have shown that allergy shots may stop asthma from developing in children with nasal allergies.

How They Work

Allergy shots may “turn down” your reactions to the things that you are allergic to. The shots do not cure your allergies, but you will have fewer symptoms and need to use less medicine.

It is important to stay on schedule with your allergy shots. If several weeks have passed since your last shot please call and speak to an allergy nurse, 203-432-8797. We may need to change your dose before your next shot.

How long to I have to keep getting my allergy shots?

There are two phases to allergy shot therapy: a build-up phase and a maintenance phase.

  • Build-up phase: In this phase you will start with a low dose injection and build to a higher dose of allergens over time. For typical immunotherapy this phase lasts from 6 to 10 months, depending on how often you get your shots and how well you tolerate them. The build-up phase for venom therapy generally lasts for 10 weeks.
  • Maintenance phase: When you reach your “effective therapeutic dose” you will begin the maintenance phase. During this phase you receive your allergy shots less often, usually every 3 to 4 weeks. The maintenance phase typically lasts 3-5 years (or longer if advised by your allergist).

Reactions to allergy shots

Reactions to allergy shots are common. Most reactions are local (redness and swelling where you got the shot). Rarely, reactions can affect your entire body. This is referred to as a systemic reaction, and it can be dangerous. For this reason you must stay in our office for 30 minutes following every shot appointment. Additionally, you should not exercise for 2 hours after your shots.

If you are having asthma symptoms when you are scheduled for an allergy shot it is important to tell your nurse. Allergy shots can worsen asthma symptoms.

Local reactions

Local reactions are the most common. They can vary from a dime-sized itchy spot to a large lemon-sized swelling. You may need to take an antihistamine (like Benadryl), and apply ice to reduce your reaction. If you have a local reaction tell your allergy nurse at your next visit. If a local reaction lasts longer than 24 hours or happens often your allergist may change your allergy shot schedule.

Systemic reactions

Systemic reactions include:

  • stuffy or runny nose
  • sneezing
  • cough
  • itchy or red eyes and ears
  • itching or tightness of the throat
  • hives
  • flushing
  • lightheadedness
  • chest tightness
  • wheezing,
  • and rarely, life-threatening reactions (including difficulty breathing and/or a dangerous drop in blood pressure ).

Most systemic reactions are mild and improve with treatment, but these reactions may become life threatening. If you experience a systemic reaction in the office tell a nurse right away. The nurse may give you an injection of epinephrine (EpiPen®) or another medication to quickly relieve the symptoms. You may need to be transported to the Yale New Haven Hospital Emergency Department for further treatment and observation.

We will prescribe an epinephrine auto-injector (aka EpiPen®) for you to have with you on your allergy shot days. If you have a systemic reaction after you leave the office, you may need to use your EpiPen® and go to Yale Health Acute Care or a local emergency room for further treatment.

Changes in your health

If at any time during the course of your immunotherapy you develop a new medical condition, you become pregnant, or you start a new medication, please tell the nurse. In particular, high blood pressure or heart medications and certain antidepressants cannot be taken with allergy shots. You should not get your allergy shot if you are have a fever, rash, asthma symptoms, or increased allergy symptoms.