Allergy shots, also known as immunotherapy, are a long-term treatment that reduces your sensitivity to substances that cause allergies. Some substances that commonly cause allergies are:
- Pet dander
- Dust mites
Allergy shots are not used to treat allergies to food, latex, or medicines.
To find out which substances cause your allergies, you will have skin tests. Based on your test results, a special mixture will be prepared for you with extracts of those substances. Then, you’ll get a series of shots. At first, the mixture will be diluted (weak). It will gradually get stronger. Over a period of months, the shots can help “turn off” your allergic reactions.
Every patient is different, but allergy shots are usually very effective for seasonal allergies. Many people find that their allergies improve so much that they can stop taking their regular allergy medications.
Allergy shots are less effective in some patients who have asthma because their asthma is not the result of allergies. Even so, about half of patients with asthma have an improvement in their asthma symptoms because of allergy shots. Although allergy shots generally are considered safe and effective, no treatment outcome is guaranteed.
If your allergies are not controlled by avoiding the things you’re allergic to, or by allergy medicines, see your doctor. Your doctor may recommend allergy shots.
Your doctor may also recommend allergy shots if you have had a serious allergic reaction to an insect sting. Allergy shots can make you less likely to have a serious reaction again if you are stung in the future.
Side effects can be local or systemic.
- Local reactions happen at the site where the shot was given.
- Early reactions — you can experience itching, redness, or a hive (bump) soon after a shot.
- Later reactions — about 8 to 12 hours after a shot you can experience swelling and soreness.
- Systemic reactions are rare and usually happen within 30 minutes after getting a shot. Patients who have heart disease and those with uncontrolled asthma are at higher risk for systemic reactions. Systemic reactions can include:
- Itchy, watery eyes
- Asthma (chest tightness and wheezing)
- Itchy hands, throat, or feet
- Shock or death
You don’t necessarily have to stop getting allergy shots if you have a systemic reaction, but you will be monitored more carefully and your provider might suggest steps to reduce the chance of another systemic reaction.
- Most people start by receiving two shots each week, with at least one day off between shots.
- After about six weeks, they get a shot once a week.
- Beginning at three to four months, the get shots every four weeks. This is the maintenance phase of treatment.
- Most patients stay on a monthly schedule for 5 years, so this is a long-term commitment.
The patient must stay in the clinic for 30 minutes and be checked by a nurse after each shot. Most reactions to allergy shots happen within 30 minutes, and the clinic staff will take care of you if you have a reaction.
You play an important role in making your immunotherapy successful and safe:
- Get your shots on schedule. If you miss or skip shots, you might have to start the treatment over again.
- But, don’t get a shot if you feel sick, have a fever, or have had asthma symptoms in the past 24 hours.
- Tell your provider about any reactions (side effects) you notice after an allergy shot.
- Carry an EpiPen with you on days you plan to have a shot. Know when and how to use an EpiPen to treat a reaction.
- Keep taking your other allergy medications as usual, including prescription and over-the-counter medications. It can take a few months before your allergy symptoms improve after you start immunotherapy.
- If you get pregnant, tell the allergy department and your doctor right away. You can safely continue with immunotherapy, but your dose might need to be adjusted.