When and How To Conduct Oral Food Challenges

November 19, 2018
Tom Castles

Demystifying the oral food challenge starts with understanding its risks and benefits.

Dave Stukus, MD

There are few physicians better poised to offer insights into the right situations and methods for oral food challenges than Dave Stukus, MD. At his busy academic center in Columbus, Ohio, Stukus and colleagues conduct between 20-25 oral food challenges per week. In his own more than 10-year career as an allergist, Stukus has conducted no less than a thousand oral food challenges.

A lot of allergists are interested in oral food challenges. So why are some so wary of the practice and what are their big concerns?

Shortly after hosting a presentation on the topic in front of a standing-room only crowd at the annual meeting of the American College of Asthma, Allergy and Immunology in Seattle, Washington, we caught up with Stukus to learn more about when and how to conduct oral food challenges.I think the overarching thing we hear is that it's a difficult thing to do oral food challenges in a busy clinical practice. You need to have dedicated exam rooms where you can stay for several hours, and you need to have support staff that's available in case an allergic reaction occurs so you can drop everything and treat them immediately if that happens. Working that out in an outpatient center that may be miles away from a medical facility or an emergency room is understandably logistically challenging for a lot of folks.

What evidence supports oral food challenges? If I was a physician on the fence about it, how would you help me arrive at a decision?

Also, with the specialty of allergy and immunology, there are a lot of folks who don't have a comfort level in treating young infants and children. Therefore, they may be more reluctant to do oral food challenges in that subset of the population.It's widely believed that oral food challenges are the gold standard and absolute best test to diagnose food allergy. They can be used at the time of initial diagnosis when the clinical history and/or IgE testing is indeterminate, or to determine if somebody with known food allergies develops tolerance over time. So, that's really the best way to figure this out.

We know that with food challenges, if you select the patient properly, prepare the patient and/or family ahead of time regarding what to expect and the potential for a reaction to occur, and we proceed slowly, it's very safe to do.

There's a misconception that if somebody has a reaction during a food challenge that it's going to be all or nothing and they're going to immediately have a life-threatening allergic reaction, but that's not what we see generally. So when patients pass the test and they're able to eat a couple of servings of food without having any reaction and they're no longer considered allergic, that's a life-changing moment for them. They may not have to avoid their allergen and sometimes they won’t have to carry epinephrine anymore. It can change everything about how they navigate the world.

Can you point to a particular case of an oral food challenge that you want to highlight as an example for other physicians to follow?

Even when people have symptoms during a challenge, they also have improved quality of life because 1) it proves that they're allergic, so it removes any question; 2) It reinforces the need to follow food allergy management strategies; 3) It teaches them exactly what an allergic reaction would look like, and most importantly; 4) They see how quickly symptoms subside when you give them the proper treatment. So it's a real life example that occurs in a very safe clinical setting under supervision, that demonstrates to people that this is what it would look like if you're out to a restaurant or in school and you start to have an allergic reaction, and this is how it should be treated.Some of the more dramatic examples are people who take an allergy avoidance strategy because they have a incomplete understanding of true risks. For example, I met a family that felt because of their child's peanut allergy that they couldn't send their child to school. They didn't go to church anymore, they were too afraid to go to a restaurant, or even to walk inside a grocery store. They never went trick-or-treating. It’s extreme stuff, because they thought that if you accidentally touch a peanut you could die. Well, lo and behold, his allergy tests were very mild but nobody was willing to do the oral food challenge because they were worried that a peanut challenge in the young child could cause a severe reaction.

I was willing to do that, so they drove 10 hours to come see me. He passed the challenge just fine. It turned out he was never allergic in the first place! I still get updates from them almost 2 years later about his first time trick-or-treating, a field trip for kindergarten and first grade, and simple things like enjoying Thanksgiving like everybody else. It was a dramatic, emotional, life-changing experience for this family.

What sort of questions do you get about oral food challenges?

I have other examples where it's adolescents that have been avoiding a food for their whole lives. Now they're heading off to college or just scared of the unknown. They have no idea what would happen if they were to accidentally eat something, so they'll do a challenge sometimes even knowing that they might potentially react. But we do it in a safe way, and then whenever they do have symptoms, we treat them immediately. They're usually mild with some itching or hives or maybe upset stomach, but they get better. These folks say that it was a really helpful exercise to go through, because they were thinking that if they accidentally took a bite of something or have even a trace amount that they would die immediately.There are two themes to the questions. One is that a lot of people are making the diagnosis of food allergy based on testing alone. We spend a lot of time talking about why the clinical history is the most important part in making a diagnosis and how the tests that we have available are not the end-all-be-all and should not be interpreted as positive or negative. There's a scale that determines the likelihood that somebody is allergic and I think there's a lot of questions in regards to that.

So how about that second question? What sort of advice do you give on incorporating oral food challenges into practice?

What's the key takeaway for those interested in oral food challenges?

And then the second part is about how do I make oral food challenges work in my busy office setting? I want to do the right thing. I want to help my patients, but I'm stuck with my current office setup. What can I do to change that?It's really about getting comfortable, and kind of reinforcing that we all receive the specialized training during fellowship as allergists. Really, we’re the experts when it comes to this. Other physicians don't receive the proper training in regards to oral food challenges, or in the recognition of anaphylaxis. So if our patients can’t rely on us, who can they rely on? It's really all about that positive messaging and trying to build some confidence through that. It’s also important to begin thinking about the logistics of how their flow goes inside the clinic setting. How many rooms do they have? What's the support staff like? What kind of experience do they have with food challenges already? What are some limitations that they're having now? Everybody has a little bit of a different case.

It's the most important part of establishing a diagnosis -- either establishing a diagnosis of food allergy and food allergy management to determine if someone's no longer allergic. There's just no getting away from it. It can be anxiety-provoking for patients and families, and rightfully so, but if we've approached it in a reassuring way and we follow safe, standardized ways of doing it, they can be a huge benefit.