Oral Immunotherapy (OIT)

What is oral immunotherapy?

Oral immunotherapy (OIT) is a treatment for food allergies. Under the care of an allergist, you eat very small amounts of the food you’re allergic to (allergen), increasing the dose over time. The goal is to reach a point where you won’t have a severe reaction if you accidentally eat a small amount of your allergen.

Food allergies happen when your body mistakenly thinks a protein in that food is going to harm you. In an attempt to protect you, your immune system creates an allergic reaction, which can sometimes be life-threatening. Oral immunotherapy introduces the allergen to your body very gradually over time. This way, your immune system gets used to it and stops seeing it as something harmful (also called desensitization).

What does OIT treat?

Oral immunotherapy can treat any food allergy, though most studies on effectiveness focus on peanut allergies.

How do I prepare for oral immunotherapy?

Before starting OIT, you might need to:

• Get allergy skin tests and blood tests. This confirms a food allergy and provides a baseline IgE number to compare with to know if OIT is working. (IgE is an antibody that can indicate a food allergy.)
• Make sure asthma and eczema are well-managed. Having other allergic conditions or conditions that affect your lungs can put you at higher risk for a serious reaction.
• Purchase measuring devices and the food you need to eat for OIT doses. This might be a powder (like Palforzia® for peanut allergies), a paste or another form.
• Get an epinephrine auto-injector (EpiPen®, Auvi-Q®). Your healthcare provider will give you a prescription for the auto-injector. You won’t be able to start OIT without it.

What happens during oral immunotherapy?

During oral immunotherapy, you (or your child) will start by eating a very small amount of your allergen (depending on the food, it could be an amount that would fit on the tip of your pinky finger). Under your provider’s guidance, you’ll eat the same amount every day, increasing the amount every two weeks. You’ll continue this until you reach a certain amount (set by your provider), unless you have a severe reaction or otherwise need to stop.

OIT happens in two phases: the updosing phase and the maintenance phase. If you experience a reaction at any point, your provider may move you down to the last successful dose or discuss other options with you.

Updosing

During the updosing phase:

• You’ll have an initial appointment at your provider’s office, where you’ll eat a small amount (dose) of your allergen — your provider will tell you how much and how to measure it. Your provider will observe you and treat you if you have a reaction.
• You’ll eat the same dose of allergen every day, around the same time each day.
• You’ll return to your provider’s office every two weeks to increase the dose in small increments.

Some people have updosing appointments every week and eat two doses of allergen each day. Follow the OIT schedule your provider gives you.

Maintenance

Once you reach a certain dose set by your provider, you’ll start the maintenance phase. You’ll continue eating the last successful dose every day for at least six months. At the end of six months, your provider may repeat your blood tests to see if you have fewer antibodies to your allergen.

You may also have a food challenge test to see if you can eat your allergen — and how much — without a reaction. Depending on the results of blood and food challenge tests, your provider may recommend continuing to eat the same dose daily, or you may be able to eat a larger amount of your allergen a few days per week. You’ll still need to carry an epinephrine auto-injector with you in case of an unexpected serious reaction.

What restrictions do I have during oral immunotherapy?

Your provider may ask that you follow some guidelines during OIT. Following them can reduce your risk of an allergic reaction and help you be prepared if you have one. These include:

• Always have allergy medications and a current (non-expired) epinephrine auto-injector with you when you take a dose.
• Eat a meal before taking your dose (don’t take a dose on an empty stomach).
• Take your dose within two hours of the time you took the previous day’s dose. For instance, if you took your dose at 8 a.m. yesterday, take today’s dose no earlier than 6 a.m. and no later than 10 a.m.
• Avoid lively physical activity and hot baths right before and for two hours after a dose.
• Don’t take ibuprofen (Advil®, Motrin®) for three to four hours before and after your dose.
• Don’t take your dose if you have a fever, cough, vomiting or other illness. Being sick can make you more likely to have an allergic reaction. You might also miss symptoms of an allergic reaction if they’re similar to the illness you’re experiencing.
• Always talk to your provider if you need to miss a dose. They may give you special instructions on how to proceed.

What should I do if I have a reaction during oral immunotherapy?

Your provider will give you instructions on what kind of reactions to look out for, when to use your epinephrine injector and when to go to the emergency room. Use your epinephrine injector and call 911 (or your local emergency services number) if you experience:

• Swelling of your face, lips, tongue or throat
• Difficulty breathing
• Chest tightness
• Multiple hives
• Vomiting
• Tingling hands, feet or lips
• Feeling weak, dizzy or faint
• Feeling of impending doom

How long does oral immunotherapy last?

The updosing phase of oral immunotherapy usually takes about six months (but can take longer if you need to skip updosing or go back to a lower dose at times). The initial maintenance phase is six months. After that, you’ll continue eating your dose daily or a few times a week — depending on your provider’s recommendation — to remain desensitized.

Your provider may repeat blood tests to check your numbers every six months to a year after that.

What are the potential benefits of oral immunotherapy?

The goal of oral immunotherapy is to desensitize you to your allergen so that if you’re accidentally exposed to it, you won’t have a severe reaction. Providers sometimes call this “bite proof.” Some people can freely eat foods they were once allergic to after completing OIT, though this is more common in younger kids. This can improve your quality of life and reduce worry about eating foods that could cause a reaction.

How successful is oral immunotherapy?

Studies suggest that oral immunotherapy is often successful at desensitizing kids under 4 to the food they’re allergic to. But this can depend on a lot of factors, including age, length of treatment and the specific allergen. For instance, in studies of OIT for peanut allergies, over 70% of kids between the ages of 1 and 4 were desensitized to at least 300 milligrams (mg) of peanut protein (the equivalent of about one peanut).

What are the risks or complications of this treatment?

The main risk of oral immunotherapy is anaphylaxis, a severe allergic reaction. This is why you should never try to create an OIT program on your own and updosing is always done in a provider’s office. You may also experience minor reactions, like a single hive or mild belly pain. Your provider will give you a plan that tells you what to do if you or your child have a reaction at home.

OIT also raises your risk for eosinophilic esophagitis, a potentially serious condition that causes inflammation in your throat. Let your provider know right away if you or your child have symptoms of eosinophilic esophagitis, like vomiting or a feeling of food getting stuck in your throat. Your child may refuse to eat if they’re having symptoms. The condition usually resolves when you stop OIT.

When should I call my healthcare provider?

Contact your provider if you or your child:

• Have any kind of allergic reaction during OIT
• Need to miss a dose
• Have any questions or concerns about your treatment

What is the best age to start oral immunotherapy?

Generally, oral immunotherapy is more likely to be successful the younger you start. But a lot of factors can go into your decision. Talk to your provider about any concerns or questions you have about the best time to start.