Emerging Treatments: Immunotherapy for Food Allergies

Food allergies affect 15 million people in the United States. With age, some of these allergies can be outgrown, while others are life-long. Currently, there is no cure for a food allergy and few treatments. Doctors hope to soon change that.¹

There is a great deal of promising research underway on new methods to treat food allergies. Immunotherapy is an example of an emerging treatment for certain types of food allergies. It shows promise in reducing a person’s allergic reactions to foods.^1,2

How does immunotherapy work?

Immunotherapy is a process of desensitization. It is training the body to be less responsive to an allergen and have a less severe allergic reaction when it comes into contact with that allergen. By continuously and gradually increasing exposure to a particular allergen, the immune system can become less sensitive. This results in a decrease in symptoms when exposure does happen.^1-3

This process also increases the threshold of reactivity, meaning more allergen is needed to trigger a reaction.^1-3

Types of immunotherapy

Immunotherapy for food allergies can be done various ways:¹

• Oral (eaten)
• Sublingual (under the tongue)
• Epicutaneous (on the skin)

Oral immunotherapy

Oral immunotherapy (OIT) is taken by mouth. It involves slowly eating larger amounts of an allergen. The goal is to raise the threshold that triggers a reaction. It has been studied in different food allergens, including:^1,3-5

• Milk
• Eggs
• Peanuts
• Tree nuts
• Fruits and vegetables

With OIT, very small doses of the allergenic food are eaten daily. The dose increases on a schedule. It can take 6 to 12 months to reach the maintenance dose, which is the goal dose. After this, the maintenance dose is eaten each day to maintain tolerance.^1,5

OIT must be closely supervised by a doctor. It is a long-term treatment and requires regular office visits. This is so the doctor can judge how well you tolerate each increased dose. Not everyone can tolerate the increased doses. Some people have severe reactions to immunotherapy. This is especially true for people with peanut allergies.^1,3,5

OIT is not a cure for food allergies. It is intended to provide protection in case of accidental exposure to the allergen. It raises the threshold that can trigger an allergic reaction and can be safe for some people with food allergies.^3,5

In 2020, the U.S. Food and Drug Administration (FDA) approved Palforzia® [Peanut (Arachis hypogaea) Allergen Powder-dnfp] as the standard OIT product for peanut allergy.³

Sublingual immunotherapy

Sublingual immunotherapy (SLIT) is placed under the tongue. The allergen is dissolved in a liquid or is in a dissolvable tablet and held under the tongue before being swallowed or spit out. The allergen is in contact with the cells that line the mouth. SLIT has been studied in different food allergens, including:^1,4,5

• Peanuts
• Hazelnuts
• Milk
• Peaches

Like OIT, SLIT starts with tiny doses and is gradually increased to a maintenance level. The purpose is to boost tolerance and reduce symptoms from exposure to allergens. This increases the threshold before an allergic response. SLIT uses smaller doses than oral immunotherapy. It also requires daily dosing of the food to maintain desensitization.^1,3-5

Sublingual immunotherapy has fewer side effects than OIT but appears to be less effective. Symptoms are generally mild and tend to affect the mouth and throat. So far, the FDA has not approved any SLIT treatments.^4,5

Epicutaneous immunotherapy

Epicutaneous immunotherapy (EPIT) is given on the skin. An adhesive patch is applied each day. It is another way to desensitize a person to a food allergen. Like other forms of immunotherapy, the dose must be given daily to reach and maintain desensitization to the food. The patch has a fixed dose.^1,4,5

Viaskin® Peanut patch is a non-invasive treatment option for children living with peanut allergy. It works by transferring the peanut protein from the surface of the skin to reach and stimulate the immune system. It can do this without entering the bloodstream. It is being studied in clinical trials and is not commercially available.^1,4,5

Who is a good candidate for immunotherapy?

Understanding how each form of immunotherapy works is important. Increased risk of reactions and side effects can vary based on type of food allergy and type of immunotherapy.

Things like age, ability to stick to a schedule, and potential for reactions must be weighed when considering whether to start immunotherapy and what type of immunotherapy to start.¹

Having realistic expectations

It is important to have realistic expectations of immunotherapy. The basic goals of this treatment are to prevent severe reactions caused by accidental exposure to foods. This may offer additional protection beyond strict avoidance followed by treatment with epinephrine in cases of anaphylaxis.^3,5

Longer-term objectives include finding ways to create a permanent tolerance and regain the ability to eat previously allergic foods.⁵

There is ongoing research to determine whether immunotherapy can help a person develop permanent tolerance. Longer-term studies will tell us how appropriate each type of immunotherapy is for different types of food allergies and ages. One day, immunotherapy is likely to become part of the routine management of food allergies.^1,5