Improving Food Allergy Testing

Food allergy diagnoses have risen in the past decade, but confidence in accurately testing for the condition is at an uncertain level.

In an interview with MD Magazine® while at the American College of Allergy, Asthma & Immunology (ACAAI) 2019 Scientific Meeting in Houston, Whitney Morgan Block, MSN, CPNP, FNP-BC, president, chief executive officer, and co-founder of the National Allergy Center (NAC), and Teresa Neeno, MD, fellow NAC co-founder, explained how food challenges persist as the most reliable method of food allergy screening.

That said, the strategy has its own faults.

MD Mag: Do we have hope for improved testing methods in food allergy?

Block: I think that researchers are working on better blood tests. Pretty much, the 3 tests that we have are the blood test, the skin test, and the food challenge. All of them have pros and cons.

I always say that the blood test and skin tests are not really diagnostic tests—they're tools to help us determine what the likelihood is that somebody would have a reaction, if they were to eat the food. So, they're not going to actually tell you if you actually have a food allergy. The only one that's a real true diagnostic test is going to be the food challenges.

Food challenges are time-consuming, they can be risky, they can be anxiety-provoking. So, there's a lot of reasons not to do food challenges, and that's the reason why I think a lot of allergists and patients are really frustrated—because there's a lot of reasons not to. And you really need to find an allergist that looks for the reasons to do food challenge.

And I feel like everybody practices differently, but I know that we do tons of food challenges, and the reason why we do is because we're always looking at the bright side—trying to say, ‘We're hoping that you're not going to have a food allergy,’ and the blood tests, skin tests, and your history points to the likelihood is low that you're going to.

Or, maybe it's kind of like, in between—it's a toss of a coin, so let's do the food challenge. If you're willing to, we're set up for any kind of reaction. We know how to treat anaphylaxis, we know how to treat any kind of allergic reaction, we're set up for that. We do a lot more food challenges—I didn't even realize, because I worked at Stanford for 6 years, and so I'm used to do like 8-10 food challenges in a day. When I get out and talk to other allergist, I realize that they do like 1 a week, 2 a month.

Neeno: It depends. It really depends on the practice.

Block: I mean, it’s crazy.

Neeno: There's some allergists that are much more comfortable doing food challenges, but I think it's that story—it's the patient, it's the person sitting in front of you and what reactions they had, or had they not have any reactions.

And I think we owe it to them to give them a definitive answer on yes, based on the testing and your challenge and everything, you're allergic, but we can treat that. We can help, so that you can go out to eat, you can live life, and not worry that you're going to have a reaction, or have much less worry, because we can do things to treat it now, which is exciting.