Oral Immunotherapy, known as OIT, is one of several food allergy desensitization treatments conducted under close medical supervision by allergists. It involves giving patients progressively larger doses of the allergen, followed by ongoing, daily maintenance doses, to increase and maintain tolerance. Though it has worked for many patients, OIT is not a cure for food allergy, particularly given the fact that when the therapy is discontinued, tolerance hasn’t been shown to persist indefinitely. And unfortunately, the treatment doesn’t work for everyone.
We spoke with two parents of children who have undergone OIT treatment – one, successfully, and the other, unsuccessfully. Their stories highlight how individuals respond differently to medical treatments.
Successful Desensitization: One Family’s Story
The Custodio family
First, Amanda Custodio of Oakville, Ontario, describes her 10-year-old son Nate’s successful experience with OIT.
Can you tell us about Nate’s food allergy/allergies? What allergy/allergies is he managing? How severe are they, and when was he diagnosed?
We learned that our son was allergic to peanuts when he was two years old, and reacted severely after ingestion. From the point of diagnosis, we avoided peanuts and any foods that may have been exposed to them, and carried epinephrine auto-injectors with us at all times. One of the scariest reactions that our son had was after drinking hand-squeezed lemonade at an outdoor festival. He is not allergic to lemons or water, but the person who squeezed the lemon must have had peanut residue on her hands. From that point on we realized that food allergen avoidance wasn’t enough.
How did you come to learn of OIT, and which allergist did you work with?
We learned about the potential of OIT and of being part of a study from an article in Allergic Living magazine featuring Dr. Susan Waserman’s work. We contacted our pediatric allergist who referred us to Dr. Waserman’s office, at which point we were put on a waiting list.
What was the OIT process like for you and your child? What did it consist of? How long did it take?
The process began with an initial screening and assessment, as well as confirmation that our son was a candidate for the study. Each day we mixed flour with yogurt for our son to eat. This was the toughest part for us. Most parents were mixing it with chocolate pudding, which our son doesn’t like, so we needed to find an alternative. For six months OIT meant trips to McMaster Children’s Hospital every other week for dose increases and observation. Thereafter, we visited quarterly, and now we check in annually. For our son, these trips were always special. He loved Dr. Waserman’s nurse Tosha, and he enjoyed his special time alone with Mom. We also treated him with a new Lego set after each visit so that he didn’t have negative childhood memories of the hospital.
How did OIT work or not work for your child?
Successful completion of OIT means that our son eats two peanuts each day after dinner. He still finds the taste aversive, but understands that eating two peanuts daily will be part of the rest of his life. We openly speak about how OIT has changed our lives and what the specific impacts mean for him. For example, now he can go to Dairy Queen after baseball games and eat with his team.
Do you have any additional comments about your experience?
OIT has been absolutely life-changing for our family and we will be eternally grateful to Dr. Waserman and her team. We will now fly across water, visit resorts and restaurants, and let our son play and eat freely at friends’ homes. I would encourage all parents of children with life-threatening allergies to research OIT.
And when it doesn’t work: Another parent shares her story
Demonstrating how different individual responses can be to desensitization efforts, we turn to the experience that Vancouverite Ewa Chang and her family had with OIT. Her 10-year-old daughter Isabelle was eight years old at the time they attempted treatment.
Can you tell us about Isabelle’s food allergy/allergies? What allergy/allergies is she managing? How severe are they, and when was she diagnosed?
Izzy is allergic to milk, eggs, tree nuts and peanuts. We had officially diagnosed her allergies when she was about five months old, though signs were present right away which included skin rashes and eczema, issues with digestion, and spontaneous hives. She is extremely allergic to casein (milk protein), and is at high risk of anaphylaxis from even minimal exposure to the protein.
How did you come to learn of OIT, and which allergist did you work with?
I learned about the OIT study from one of the local Facebook groups dedicated to families living with allergies. We participated in the Montreal Milk Desensitization Study which was overseen by Dr. Edmond Chan in Vancouver at the BC Children’s Hospital.
What was the OIT process like for you and your child? What did it consist of? How long did it take?
The process consisted of an initial assessment, including skin and blood tests for milk allergies, as well as an oral challenge at a later appointment to confirm milk allergy. Once Isabelle was considered a good candidate for the study, she was accepted as a participant. At her initial visit, she was given a 1 mL solution containing diluted milk. She was monitored for about an hour. When no reaction occurred, we were sent home to continue the diluted 1 mL dose once per day for a week. We met with Dr. Chan on a weekly basis at the allergy clinic at the BC Children’s Hospital, each time increasing the dose at the clinic, then continuing with that dose at home daily. After a few successful weeks, Izzy’s asthma started acting up, so we stayed on the last dose for a few weeks until it was brought under control. We then resumed the increases, but at a reduced rate.
After several months of trying, and more severe reactions to higher doses (including a couple of episodes requiring epinephrine and hospitalization), Dr. Chan felt it was best to stop the OIT. He recommended that Izzy continue with daily ingestion of a dose she had tolerated without any reactions. We continued with a reduced dose for a few months (outside of the study with no escalation), but eventually she was starting to have more frequent minor reactions so we lowered the dose again, until we eventually stopped altogether.
[*Editor’s note: Asthma, especially if uncontrolled, may increase the chances of OIT not working]
How did OIT work or not work for Isabelle?
Unfortunately, OIT did not work for Isabelle. It was disappointing, as the time and sacrifices she had to make were quite substantial. She had to avoid any overheating, exercise, or brisk activity for two hours after each dose, and needed to be monitored during that time. It was also recommended to take each dose with food. This limited the times and activities we could participate in.
Do you have any additional comments about your experience?
Izzy really disliked taking the milk, and was relieved when we finally stopped altogether. She would get anxious before every dose. Even several months later, she still hated the taste. She never got over the aversion she had to the taste of milk, even when we tried disguising it with chocolate syrup, or mixing it in with other foods. The psychological impact the study had on her, and the emotional stress she endured every time she was ingesting her daily dose, could not be ignored either.
When after a few weeks she started having somewhat regular minor reactions, she asked me why I was trying to change her. It’s difficult to hear this from your child, and even more difficult trying to explain the long-term benefits of OIT being successful. In the end, I am glad we were able to participate, as this experience taught me and Isabelle many valuable things about her specific allergies.
That being said, I am concerned that at the end of this study, her blood IgE levels were at significantly increased levels from what they were at the start. This is apparently common at the early stages of OIT, but then numbers typically drop as the body becomes desensitized. Since we never completed the OIT study, I fear what this will mean for her in the future should she have accidental exposure to milk.
The above experiences are just two of the possible outcomes of OIT. There are many families who experience positive and not-so-positive outcomes with any therapy.
Other types of food allergy treatment currently being studied by allergists in research include such therapies as anti-IgE antibodies (Xolair®), Chinese herbal formulas, and other types of immunotherapy, such as Sublingual Immunotherapy (SLIT), and Epicutaneous (EPIT). We will be offering you a glimpse of families’ experiences with these protocols in the months to come, stay tuned!
Tags: Community Stories, OIT, Oral Immunotherapy, Research