Allergy Shots: What about them?

It’s past midnight and while the rest of the city is sleeping, Leny is busy doing advanced reading. It has been her childhood dream to become a nurse, and now that she is in college, this is her shot to make that dream possible. Thus, she spends much effort to do well not only in academics, but in her clinical duties as well.

She’s scanning her book as she comes across allergy shots.

“What? Allergy shot? Is there even such a thing?” she asks herself as she gets both curious and intrigued by the concept and proceeds to reading more about it.

Allergy shots: An overview

Allergy shots are a form of treatment called immunotherapy. It contains a tiny amount of the specific substance or substances that trigger allergic reactions, called allergens. These shots contain just enough allergens to stimulate the immune system, but not enough to cause a full-blown allergic reaction.

In other words, allergy shots help the body get used to allergens (desensitization). However, they don’t cure allergies, but eventually the symptoms will get better, the immune system builds up a tolerance to the allergens and the person who gets this shot may not have allergic reactions as often.

Allergy shots may be indicated if:

  • it’s impossible to avoid the things that cause the allergic reactions — and allergy medications don’t control the symptoms well;
  • Allergy medications cause bothersome side effects or interactions with other medications the person needs to take;
  • The patient wants to reduce the long-term use of allergy medication;
  • The patient is allergic to insect stings

It may also be used to control symptoms triggered by:

  • Seasonal allergies since once a person has seasonal allergic asthma or hay fever symptoms, he/she may be allergic to pollens released by trees, grasses or weeds.
  • Indoor allergens. If the patient has year-round symptoms, he/she may be sensitive to indoor allergens (dust mites, cockroaches, mold or dander from pets, such as cats or dogs).
  • Insect stings. Allergic reactions to insect stings can be triggered by bees, wasps, hornets or yellow jackets.

However, allergy shots aren’t available for food allergies or chronic hives (urticaria).

Since allergy shots contain substances that cause allergies, reactions are possible, and can include:

  • Local reactions, which can involve redness, swelling or irritation at the injection site. These common reactions typically begin within a few hours of the injection and clear up soon after.
  • Systemic reactions, which are less common — but potentially more serious. You may develop sneezing, nasal congestion or hives. More-severe reactions may include throat swelling, wheezing or chest tightness.
  • Anaphylaxis is a rare life-threatening reaction to allergy shots. It can cause low blood pressure and trouble breathing. Anaphylaxis often begins within 30 minutes of the injection, but sometimes starts later than that.


Preparation for this treatment includes:

  • Avoiding exercise or doing anything strenuous for two hours before and after the appointment since exercise may increase blood flow to the tissues and cause the allergens to get into the blood faster.
  • Informing the doctor about any other medicines or herbs and supplements the patient is taking. Some medications interfere with the treatment or increase the risk of side effects. The patient may need to stop allergy shots if he/she is taking these medications.
  • If the patient is pregnant or planning to get pregnant, she must ask the doctor whether she should continue to get allergy shots.
  • Before starting a course of allergy shots, the doctor may use a skin test to determine that the reactions are caused by an allergy — and which specific allergens cause the signs and symptoms.
  • During a skin test, a small amount of the suspected allergen is scratched into the skin and the area is then observed for about 15 minutes. Swelling and redness indicate an allergy to the substance. The doctor may also use an allergy blood test.
  • Healthcare professionals must also be informed if the patient is not feeling well, especially if he/she has asthma or has had any symptoms after a previous allergy shot.

After the treatment

  • The patient may be asked to stay at the doctor’s office for about 30 minutes after receiving an allergy shot to make sure that he/she doesn’t develop side effects such as itchy eyes, shortness of breath, runny nose, or tight throat.
  • If these symptoms appear after the patient leaves, he/she must be advised to go back to the doctor’s office or go to the nearest emergency room.
  • Redness, swelling, or irritation right around the site of the injection is normal. These symptoms should go away in 4 to 8 hours.

Allergy symptoms won’t stop in an instant, as they usually improve during the first year of treatment, but the most noticeable improvement often happens during the second year. By the third year, most people are desensitized to the allergens contained in the shots and no longer have significant allergic reactions to those substances.



Liane Clores, RN MAN

Currently an Intensive Care Unit nurse, pursuing a degree in Master of Arts in Nursing Major in Nursing Service Administration. Has been a contributor of Student Nurses Quarterly, Vox Populi, The Hillside Echo and the Voice of Nightingale publications. Other experience include: Medical-Surgical, Pediatric, Obstetric, Emergency and Recovery Room Nursing.

What Do You Think?