Asking About Allergies: Eating Food That Could Kill, Part 1

Hi, I’m John Kosner. I’m currently a senior at the University of Illinois in Urbana-Champaign studying Molecular and Cellular Biology with a minor in English. I’m on the pre-med track and have an interest in disability studies. I’m allergic to milk, eggs, peanuts, tree nuts and sesame. 

I wanted to learn more about oral immunotherapy (OIT) to treat food allergies, so I researched the subject for this blog post. Then, in Part 2, I sat down with Ally Kalishman, a freshman at Penn State University, and Jacqueline See-Tho, a high school junior living in Northern California, to ask about their personal experience with allergies and the decision to leap into OIT treatment. 

Think of the immune system as many different machines working together, with each machine carrying out its designated function. In a patient with one or more allergies, this immune system machinery malfunctions, so that processes that evolved to protect your body end up harming your body instead. For example, if you’re allergic to peanuts, your immune system will overproduce immunoglobulin E (IgE) antibodies that bind specifically to peanut proteins. This binding of outside proteins by antibodies is a defense mechanism for specific recognition of foreign matter, but in the case of an allergic reaction, the immune system targets a normally harmless protein, called an allergen, and falsely identifies it as an outside invader.

As a specific peanut protein is recognized and IgE antibodies bind to it, more immune system machinery becomes activated. Inflammatory responses are triggered and set into motion. Ultimately, this leads to the release of various mediators, chemical signals in the immune system that can cause symptoms such as sneezing, itching, hives, vomiting, diarrhea, coughing, shortness of breath, and even anaphylaxis, which is a serious, systemic allergic reaction that can be fatal if not treated appropriately.

The traditional and current standard treatment for food allergy is to avoid the allergen. Allergen avoidance should theoretically prevent any possible chance of anaphylaxis. Unfortunately, mistakes can happen, and even the most careful of individuals could be affected. Cross contact at restaurants, airplanes with allergens on board, and lunchrooms full of carelessness are a few of the many anxiety-inducing, potentially life-threatening situations that are hard to avoid. To protect yourself against accidental exposures, you need an up-to-date Emergency Action Plan, developed with an allergist or other appropriate healthcare provider, to follow in the event a food allergy reaction occurs. And you should always carry two auto-injectable devices with epinephrine, which is the main medication to treat anaphylactic reactions. Epinephrine constricts blood vessels, improves heart function, stabilizes blood pressure, optimizes blood flow through the body, and helps keep airways open.

Some food allergy patients may be candidates to desensitize their immune system by being exposed to their specific food allergen in increasingly larger doses until oral tolerance is achieved and they can eat the food without reacting. Oral immunotherapy, or OIT, is a treatment in which a food-allergic individual is fed increasing amounts of their allergen with the goal of increasing the threshold dose of allergen that triggers a reaction. For example, a person with peanut allergy may first be given very, very small amounts of peanut protein that would not cause an adverse reaction. Subsequently, the amount of peanut protein eaten is gradually increased in the allergist’s office under observation. This up-dosing process can take several months before a steady, daily maintenance dose is reached.

By raising the threshold that may trigger an allergic reaction, OIT can protect the patient against accidental ingestion of the food allergen. This process does not cure the food allergy, but it can allow an individual to gradually be desensitized and become tolerant to the food in their diet. The food must be eaten daily to maintain this desensitized state. Individuals who receive OIT will continue to need to carry epinephrine auto-injectors and carefully read food labels. While this treatment will not lead to ingestion of the relevant food allergen without limitation, OIT can offer newfound autonomy for some patients that previously had to accommodate their lives around allergies. 

There can be side effects with the use of OIT protocols because allergenic foods are administered in this procedure. Most symptoms are mild and can include itching of the mouth/tongue, throat irritation, runny nose, cough, nausea, heartburn, vomiting, stomach pain, and hives. One rare but potential consequence of OIT is eosinophilic esophagitis (EoE), an allergic disease that causes inflammation in the esophagus, which is the muscular tube that connects the throat and the stomach. EoE can result in difficult swallowing, vomiting and abdominal pain. Finally, there is a very small risk for the severe, life-threatening allergic reaction known as anaphylaxis with OIT. 

OIT has been performed and documented in the medical literature for many years. Most OIT protocols are not approved by the U.S. Food and Drug Administration (FDA), but in January 2020, FDA approved a peanut oral immunotherapy product called Palforzia for peanut-allergic patients aged 4-17 years. OIT has traditionally used single food allergens to treat one food allergy at a time, but OIT with multiple food allergens to treat multiple allergies simultaneously is being actively studied in clinical settings.

While OIT offers the hope of protection from food allergy reactions, there is not one single treatment approach that is appropriate for all patients. The specific risks and benefits of OIT are being assessed on an ongoing basis. Ultimately, the decision to pursue treatment is based on individual and family factors following careful discussion with your physician.

Want to hear more? In the second part of this two-part blog series, check out interviews with two young people who have opted to treat their food allergies through OIT.