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What are food allergies?
Food allergies occur when the body’s immune system mistakes a food as harmful. The food triggers reactions in the body that can range from mild (hives or swelling) to severe (vomiting or difficulty breathing). Type 1 food allergies are IgE-mediated. Common food allergies include peanuts, tree nuts, milk and eggs.
What is oral immunotherapy (OIT)?
Oral immunotherapy (OIT) is a treatment for IgE-mediated food allergies. During treatment, patients ingest small, gradually increasing doses of a specific food allergen under medical supervision. They then take a small daily dose at home to help build up tolerance against the food allergen. The goal is to increase the amount of allergen that can be tolerated before having a reaction. This reduces the patient’s risk of having a severe allergic response when accidentally exposed to their allergen.
OIT is most established for peanut allergy, with the FDA-approved pharmaceutical-grade peanut allergen powder (Palforzia™) as the only approved OIT product in the United States.
At Phoenix Children’s, peanut powder is used for OIT. We also offer OIT for cashew, sesame and walnut.
When do children typically start OIT?
A child with a food allergy can begin OIT as soon as they start eating solid foods.
What can my family expect during treatment?
Treatment usually begins with the patient eating very small quantities of the food allergen, with increasing doses over weeks to months until the maintenance dose is reached. While OIT can desensitize most patients, a continued tolerance of the food allergen after stopping therapy is less common. This means the child should continue taking a small daily dose for years to come.
What are the risks associated with OIT treatment?
Mild to moderate reactions may happen during or after dosing. They include:
- Rash and/or hives
- Itching
- Nausea, upset stomach and/or belly pain
- Diarrhea
- Runny or stuffy nose
- Sneezing
- Itching or funny feeling in the mouth or throat
- A change in behavior
Serious reactions do not happen often, but can be very dangerous if they do happen. They can lead to anaphylaxis and possibly death if not treated.
Symptoms of anaphylaxis include:
- Widespread hives, including rashes, swelling, or itching on more than one part of the body
- Swelling on any part of the body, including the mouth, tongue and throat
- Shortness of breath, coughing, wheezing or chest feeling tight
- Cramping, severe nausea or vomiting
- Significant behavioral changes and/or not “feeling right”
- Experiencing tunnel vision or feeling faint
Anaphylactic shock is the most serious allergic reaction that can occur. It can cause the airways to swell, making it hard to breathe. It may also cause a sudden drop in blood pressure. It usually happens within minutes after an OIT dose has been given. It does not happen often, but it is very important to watch for. Alert your care team if your child has any concerning symptoms during a food challenge or updosing visit.
If a reaction occurs after leaving the clinic, which is rare, follow your child’s anaphylaxis action plan and then notify the clinic after the reaction has been treated.
Review your anaphylaxis action plan regularly and administer epinephrine if your child has any signs or symptoms of anaphylaxis. When in doubt, administer epinephrine.
How many visits are needed for OIT?
Several visits are needed for oral immunotherapy. During your consultation, we’ll review your child’s medical history and explain what you and your child can expect during OIT treatments. We usually do skin prick testing and bloodwork during this first visit and throughout OIT treatments.
During the initial clinic visit, we will conduct an oral food challenge during which the food allergen is given to your child in a safe and structured manner, either as a powder or liquid, while your care team monitors your child closely for any signs of a reaction.
After this initial visit, your child will have a clinic visit every 2 to 4 weeks. During these visits, we will “updose” your child to a small amount of the allergen. Please note, these clinic visits may take 1 to 2 hours or longer if a reaction occurs.
Between clinic visits, you will need to maintain daily OIT dosing at home and complete daily logs to bring to each visit. It is very important to be consistent.
What happens after my child reaches their maintenance dose?
Eventually, your child will reach maintenance dosing. You will need to give them this maintenance dose at home each day to reduce the chance of anaphylaxis when they are exposed to the allergen by accident. Since OIT is not 100% effective for all children, we’ll give your child an oral food challenge in our clinic after one year of them being on the maintenance dose. This step is to make sure the treatment is working for your child. These oral food challenges are also done in later years to determine your child’s tolerance to their allergen.
While OIT involves a significant time commitment, most families find that it improves their quality of life knowing that their child may be able to tolerate their allergen with less risk of anaphylaxis.