Oral Immunotherapy (OIT)

We are excited to announce that our office is now offering oral immunotherapy for our patients who are allergic to peanuts. We will soon also be offering desensitization to tree nuts, milk, eggs, and wheat for eligible patients.
Working on the same principle as allergy shots for environmental allergies, oral immunotherapy entails consuming increasing quantities of an allergenic food in order to achieve tolerance from the immune system. This treatment is over 85% successful in giving patients the ability to safely eat a food to which they are allergic. Oral immunotherapy is not for everyone. OIT is time-consuming and requires commitment from the patient and their family. There is a build-up phase where we increase the body’s tolerance to the allergenic food which lasts several months to a year. During this time, there are visits to the office every two weeks, and the patient has to take the instructed dose of the food every day in between visits. After patients have reached their full maintenance dose, they will generally need to continue taking this amount of the allergenic food every day indefinitely to maintain the desensitized state. Reactions can occur during the process of allergy immunotherapy. They are often mild symptoms such as abdominal pain, mouth itching, or hives, but some patients have moderate to severe reactions requiring the use of their epinephrine auto-injector. There have been reports of patients developing difficulty swallowing and/or vomiting during or after oral immunotherapy. Overall therapy is very well tolerated and effective.

FREQUENTLY ASKED QUESTIONS

What is oral immunotherapy?

• Oral immunotherapy involves eating increasing amounts of the allergic food protein in order to desensitize the immune system to prevent it from reacting to a food to which it is sensitized. It is sometimes referred to as desensitization therapy.
• The goal of OIT is to build up enough tolerance to be able to eat a full serving of the allergenic food. After achieving desensitization, patients are often able to eat the food freely so long as they continue taking their daily dose.
• Some patients may not be interested in eating the food, and they may choose to stop at a lower dose. That dose will be enough to give them enough protection to not react if they accidentally eat a smaller amount of the food or eat something with cross-contamination.

Who is a good candidate for OIT?
• Anyone who has confirmed food allergy that is not likely to be outgrown can consider OIT. Many OIT specialists recommend waiting until a patient is over 4 years old to begin OIT, but there is evidence that starting younger children is safe and possibly more effective.
• Factors to consider if OIT is right for you or your child include the risk of having an accidental ingestion, the difficulty of avoiding the food allergen, and quality of life concerns such as anxiety and ability to participate in school and life activities. You must also consider that OIT requires time, frequent doctor’s visits, and commitment to taking a daily dose of the allergenic food.

What is the success rate of OIT?
• Over the last 15 years, numerous research studies have demonstrated over 80-90 % success in achieving desensitization.

How safe is oral immunotherapy?
• Mild reactions during desensitization are not uncommon but tend to resolve on their own. Symptoms may include hives, oral itching, and abdominal pain. More persistent abdominal pain, nausea, vomiting, or other symptoms often improve with antacids or reflux medications and adjusting the dosing schedule.
• Reactions that are moderate, severe, and even life-threatening that require epinephrine may occur, but most studies suggest this occurs to approximately 5% of patients. With treatment and dosing adjustments most of these patients are able to complete the OIT process successfully.
• There also have been patients who have developed eosinophilic esophagitis (EoE), an inflammatory allergic disorder of the esophagus that manifests as difficulty swallowing, sensation of food being stuck in the throat, reflux, and/or vomiting. This may occur in about 2-3% of patients, and it is believed that OIT revealed patients who were already susceptible.
• Eosinophilic esophagitis typically resolves if OIT is stopped. OIT specialists have had patients successfully continue immunotherapy by reducing the dose until the symptoms resolve and maintaining on that low dose for several months before further building up.
• So while OIT has serious risks, it is often well tolerated and complications while serious can be managed. The risk must be weighed against the risks and limitations of having to strictly avoid a food. In general patients who have been on OIT report drastically improved safety and quality of life without having to fear accidental ingestions.

What are other treatment options?
• Strict avoidance of the allergic food is the main other treatment option. Even with diligence accidental exposure can occur and should be treated according to your allergy action plan.
• Immunotherapy done through a wearable skin patch or a liquid held under the tongue is also in development, but research suggest these forms of immunotherapy are less effective than OIT. These methods are not as well studied as OIT.

What is the process of OIT?
• First an initial evaluation must be done to assess reaction history and undergo allergy testing if not already done.
• On the first day of desensitization, an initial microscopic amount of allergenic protein, usually mixed in water. Increasing doses of the food protein is given every 20-30 minutes over 5-8 hours under very close supervision.
• Every patient is different. Some patients will develop a reaction during the first day, at which point the reaction will be treated. After a reaction, the patient will observed for at least an hour. The last dose they safely tolerated will then be their daily home dose until the next visit.
• At home they must take their prescribed dose every day as instructed. Ideally the home dose is given around the same time daily. It should not be given on an empty stomach. The patient should only engage in light activity such as watching TV, reading, or doing homework for two hours after taking the dose. Doses should be withheld if there are any infections, fevers, acute illness, or asthma symptoms. If doses are missed, you must call the office and let us know.
• Every 2 weeks, an up dosing visit is done at the office, where the patient will be assessed and the dose will be increased to the next step. After giving the dose, the patient will be observed in the office for an hour, and any reactions will be treated as above. If the higher dose was tolerated, this dose will become your new daily home dose. You should never increase your or your child’s dose at home!
• There is flexibility in the visit schedule and visits may be spaced further apart if needed so long as you keep giving your daily home dose.

How long does OIT take?
• Usually the build-up phase takes anywhere from four months to a year. Once the full maintenance dose is reached, this dose is taken every day usually for at least 3-5 years. For many patients, they will need to take this daily dose indefinitely. Allergy testing may be updated periodically after several months of maintenance.
• After several years of maintenance, we may consider a food challenge after 4-6 weeks of avoidance to assess for what is known as “sustained unresponsiveness”, the ability to keep their tolerance to the food without needing to eat it every day. In general these patients should likely continue eating the food several times a week.

How do I treat a reaction at home?
• You should follow your written instruction sheet or allergy action plan and treat the reaction accordingly with anti-histamines and if needed an epinephrine auto-injector. After treating the reaction, you should call our office to get further recommendations.