Our immune system: vital, complex, and wonderful – except for when it goes rogue. Allergies occur when your immune system has a consistent over-the-top reaction to a relatively harmless substance (allergen) that typically doesn’t need such a response. In the US, almost a third of adults have some sort of allergy; among children, the prevalence of allergies is 1 in 4. Allergies include the ever popular hay fever, also known as allergic rhinitis, as well as reactions to insect stings and bites, asthma and eczema, and food allergies.
Allergy Symptoms
Allergens can come in all shapes and forms, with some more common than others. The same allergen may cause different symptoms in different individuals. Symptoms of an allergic reaction include:
- Itchy, watery eyes
- Itchy, runny nose
- Sneezing
- Rashes or hives
- Stomach cramps
- Vomiting and diarrhea
- Bloating
- Swelling of the skin, tongue, or throat
- Redness
- Pain
- Cough
- Chest tightness, difficulty breathing, and wheezing
- Feeling light-headed
Anaphylaxis is a life-threatening allergic reaction that needs emergency medical attention. Its symptoms typically affect several parts of the body at once, including the skin, mouth, lungs, heart, and gut. Anaphylaxis to medications is responsible for the most allergy-related deaths, particularly among older adults, but foods and insect sting allergies can also trigger anaphylactic reactions.
What is Allergy Immunotherapy?
Allergy immunotherapy is a treatment aimed at reining in that rogue immune system and teaching it to calm down. While antihistamines and decongestants simply relieve the symptoms of allergy at the time the medication is active in your body, immunotherapy works to modify the way your immune system responds to those evil allergens in the first place. The hope is that over time, your body will learn that these allergens are not so bad after all and closing your airways is not an appropriate response to peanuts.
The most common form of allergy immunotherapy is through allergy shots. After blood or skin tests to identify your triggering allergens, a tiny, controlled dose of this substance is introduced into your body through an injection, typically in your arm. Because of the low risk of a severe reaction to the shot, these treatments are always delivered in the allergist’s clinic where you can be closely monitored.
The build-up phase of allergy immunotherapy involves having these shots 1 to 3 times a week over the course of 3 to 6 months. Each injection contains an increased concentration of the allergen, which gradually stretches your immune system’s tolerance to the allergen over time.
The build-up phase is completed when your injections reach the maintenance dose. Congratulations, you’re now in the maintenance phase! The bad news is the maintenance phase typically goes for 3 to 5 years, or sometimes longer. During the maintenance phase, you receive one allergy shot a month, just to remind your immune system that it’s okay to sniff pollen.
In the long-term, some individuals can cease their allergy shots without any further reactions to the allergen while others may need ongoing maintenance shots to manage their symptoms.
Are Allergy Shots Safe and Effective?
Because allergy immunotherapy involves exposing you to your allergens, there is a risk of having an allergic reaction after your shot. In most cases, this is just a bit of a swelling and irritation at the injection site, but there is also the potential for an anaphylactic reaction, though this is rare. After your injection at the allergist’s clinic, you’ll usually be asked to wait around for 30 to 45 minutes for monitoring before being allowed to go home.
Allergy shots have been around for over 100 years, first being introduced in 1911 (though admittedly, the technique has been refined over the century). These injections are most effective for treating asthma and allergic reactions to:
- Pollen from trees and grasses
- Pet dander
- Dust mites and cockroaches
- Insect stings, such as from bees, wasps, and hornets
- Molds
Allergy shots are not usually appropriate for allergies to drugs, food, or for eczema.
An alternative immunotherapy to an injection is placing a tablet containing the allergen under your tongue, known as sublingual immunotherapy. Sublingual immunotherapy also carries a small risk of swelling or itching in your mouth, or diarrhea. This form of allergy immunotherapy is effective for asthma and allergies to:
- Dust mites
- Grass
- Ragweed
Currently, sublingual immunotherapy in the form of oral drops is not FDA-approved in the US but may be used off-label. Drops can cover a wider range of airborne allergens in addition to those treated with tablets, including pet dander, molds, and feathers.
Research is currently ongoing around allergy immunotherapy for food allergies. There is potential for techniques such as sublingual immunotherapy and oral immunotherapy to be effective, but these treatments are still under investigation.
Allergy immunotherapy has the potential to greatly improve your quality of life, so you can stop to smell the roses without a violent sneezing fit. If antihistamines and decongestant medications aren’t doing the job, perhaps what your immune system needs is a stern word from an allergist or immunologist, and a little (immunotherapy) chill pill (or shot).