Allergy Immunotherapy: How it Works and Why It’s Changing the Way We Treat Allergies

Allergy immunotherapy is a relatively new treatment that can provide long-term relief from allergies for both children and adults. Although immunotherapy was first used to treat a pollen allergy in 1911, it is now widely used to treat a variety of allergic complications, such as asthma. 

An allergic reaction occurs when the body identifies a substance as harmful and causes an immune response. People can have an allergic reaction to all kinds of things, including food, insect stings, pollen, and certain medications. The substance that causes an allergic reaction is called an allergen. Allergens can cause uncomfortable symptoms such as sneezing or itchy and watery eyes. In some cases, allergens can cause life-threatening symptoms such as asthma or swelling of the throat, threatening the patient’s ability to breathe. 

Who Might Consider Getting Allergy Immunotherapy Treatment?

Traditionally, allergy medications are used to treat symptoms of allergies. But these medications stop working once the individual stops taking them. Allergy immunotherapy can offer long-lasting results, even after the last dose. 

Allergy immunotherapy may be a good treatment option for patients who:

-Do not find relief from allergy medications 

-Have adverse reactions from taking allergy medications with other necessary medications

-Have a life-threatening allergy such as insect stings

-Wish to stop taking long-term allergy medications 

How Does Allergy Immunotherapy Treatment Work?

Allergy immunotherapy works by introducing a small amount of the allergen (the substance that causes an allergic reaction) into the body over a few years to build up a resistance and eliminate symptoms. 

How Is Allergy Immunotherapy Administered?

Subcutaneous immunotherapy (SCIT)

Subcutaneous immunotherapy (SCIT), also called injections or shots, are the most common method of administering allergy immunotherapy. Subcutaneous means “under the skin.”

SCIT works by injecting a small amount of the allergen under the patient’s skin. This is done initially once a week for a few months, then once every two weeks, and eventually once every four weeks until the end of treatment. Treatment may last three to five years for the patient to develop long-term immunity to the allergen. An added benefit of SCIT is that it may help prevent the development of new allergies in patients. 

Sublingual immunotherapy (SLIT) 

For individuals who prefer to receive treatment without injections, there is an oral treatment option called sublingual immunotherapy (SLIT). Sublingual means “under the tongue.” SLIT is administered using tablets. The patient places a tablet containing a small amount of the allergen under the tongue and keeps it there for a few minutes before swallowing it. Tablets help patients build resistance to the effects of the allergen, therefore reducing and hopefully eliminating symptoms. SLIT is repeated at least three days a week for three to five years for the patient to develop long-term immunity to the allergen.

Drops can also be used for SLIT. However, in the US, this method is currently considered an off-label treatment, meaning that it is not yet approved by the US Food and Drug Administration as an effective treatment for allergies. 

Sublingual immunotherapy only helps patients achieve symptom relief from one type of allergen and, unlike injections, does not prevent the development of new allergies. 

The Future of Allergy Immunotherapy 

Allergy immunotherapy is currently not indicated for use in children with life-threatening food allergies, although researchers are working on developing a safe and effective treatment method. Today, allergy immunotherapy for food-allergies is administered in a research setting, where children are under constant supervision. 

A study published in the Journal of Allergy and Clinical Immunology: In Practice assessed the safety of oral immunotherapy administered in a hospital or clinical setting in 270 children aged 9 months to five years old with a peanut allergy. During the study, 68 percent of children experienced an allergic reaction that was mild or moderate. Less than half of a percent of children in the study experienced a severe allergic reaction. Although severe reactions can occur in a small portion of patients, 90 percent of children reached the maintenance stage of treatment, demonstrating that immunotherapy may be a safe treatment option for young children with peanut allergies.