Allergist Scott Sicherer Tackles the Crucial Food Allergy Questions

in Features, Food Allergy
Published: October 19, 2017

New York allergist Dr. Scott Sicherer recently published an extensively updated edition of his book: Food Allergies: A Complete Guide for Eating When Your Life Depends on It. In the book, Sicherer answers about 1,000 food allergy questions in an engaging, easy-to-follow format. In the following Q&A, Allergic Living editor Gwen Smith lobs a several of our readers’ questions at the specialist, who replies with informative, engaging and sometimes surprising answers.

Gwen Smith: Let’s start with the resistance to using an epinephrine auto-injector when a person is experiencing anaphylaxis. We often hear about this. What can you tell parents about how to get past the fears they may have?

Dr. Scott Sicherer: This is a big issue. There’s never a study that comes out that says: “People are over-using this medication.” Or even that they’re using it as much as we think they should. In terms of why you should go ahead and use it: It’s safe, given in the auto-injector amounts.

The fact is that epinephrine reduces the chances of being hospitalized for the allergic reaction. It reduces, when used promptly, the chances of needing extra doses of it. This is the same medicine that used to be given years ago for treating asthma, and no one really questioned it. [With resistance to using], there could be some needle phobia, but that should be addressed as well. In my practice, people will generally say, ‘I didn’t even notice the pinch, and I just feel so much better from it.”

People need to understand the safety, the reduced need for additional medications or hospitalization, and obviously the life-saving potential of epinephrine. If you use it and you didn’t need it, nothing bad should happen. You might feel like you’ve had too much coffee. The side effects are increased heart rate, you might look a little flushed or pale or have a little headache, but all of those things go away quickly. People generally just feel better from it.

That said, I’ve yet to meet a child who says, “yes, please give me a needle.” How do you help kids not be so fearful of the auto-injector?
Author, Dr. Scott Sicherer.

SS: We have that discussion in the allergist’s office. I wouldn’t be lying to anybody, it is a needle. It feels like a little pinch, but it makes you feel better. If you’re having trouble and you don’t feel well, it’s going to make you feel better.

For children of any age, I feel there should be a supervising adult who’s ultimately responsible. But at some point there has to be a transition to self-care, as kids grow older and more independent. Having the conversation is important. We recently did a study having teenagers practice self-injection with an empty needle and syringe, just to get to the idea of: “Can I get a needle into myself?” The teens who participated and the family felt much more comfortable after that.

At Allergic Living, we receive many questions about foods of the same family. Here’s one: If a child is allergic to one legume, like either peanut or soybean, are they likely to be allergic to related foods like peas or beans?

SS: Usually not, but there are always some exceptions. Sometimes people who read your magazine fall into that that exception category. But from a population standpoint – about 1 in 20 will end up with other bean allergies. I also like to think of the fact that certain beans are more potent than others. For example, when it comes to someone who already has a peanut allergy, the beans that a bit more commonly trigger problems are green pea, chickpea, lentil and lupine. Certainly you can have allergies to those beans without a peanut allergy or soy allergy, but those just tend to be the more potent ones. Other beans – like black bean, kidney bean, white or cannellini bean – they don’t come up as often.

I don’t have a lot of data on this but, once you have someone starting to react to beans as opposed to just having a peanut allergy, then we start to worry about beans in general. You know if someone is reactive to chickpeas, we start to worry they would be reactive to lentil. Whereas, if they’ve already tolerated several beans, then we usually don’t think about it anymore.

Photo: Getty
How about this relationship: If my child reacts to dairy milk, will she also react to beef?

SS: A study a while back suggested that about 1 in 10 people with a significant milk allergy would react to beef. I think it’s probably less than that, really. But the proteins that in the cow meat have some similarities to the proteins in the cow milk. Therefore, the people who are very reactive to milk may be more likely to be to react to some of these proteins that are residual.

Now cooking the beef does break down the protein as well. So sometimes we find that someone with a significant milk allergy will have a problem with beef, but only if it’s steak where there’s some redness and blood. Whereas they might have not a problem if it’s meatballs or meatloaf or a hamburger that’s cooked through. The high estimate of cross-reactivity with someone with milk allergy is 10 percent for beef, but there are these nuances.

[The cross-reactivity] is not that common. Unless it’s an exquisite milk allergy or unless there’s some hint that there’s a problem, we don’t usually pre-test for beef allergy.

What about egg allergy? People often ask: Am I allergic to the egg white, the yolk or both?

SS: The egg white is where the major allergen is. However, we don’t typically recommend to someone with a significant egg allergy to try to separate the egg – because it’s too hard not to have any white in your food.

The big news on egg allergy is, in food studies which were started here (Mount Sinai Medical Center in New York), about 70 percent of kids with an egg allergy can tolerate it in baked goods. We believe it’s because of the extensive heating in a bakery good.

If you just took an egg and put it in the oven, it doesn’t cook in the same way as when it’s an ingredient in a muffin, which expands and has air cells and gets a lot hotter in the oven. That extra cooking seems to break down the protein enough that a lot of people can get away with eating it. And it may be that those who can and do eat it are also more likely to outgrow it in the long term.

For those with an egg allergy, talk to your allergist about whether it would be OK to add baked egg to the diet. That’s typically done through a supervised food challenge, because it potentially could still cause anaphylaxis. If you turn out to be in the 30 percent who are going to react, then the allergist should be supervising.

Another food relationship question. With cashew allergy, a lot of people wonder about problems with relatives to this nut food family, such as mangoes and pink peppercorns. How can you know if you have this issue?
Photo: Getty

Sicherer: That’s a very nuanced one, and most people do not have a problem with these related foods. But let’s start with the fact that cashew and pistachio typically go together. They have very similar proteins, and I would look at cashew as being usually the more potent of the siblings. So someone who has a cashew allergy sometimes gets away with tolerating pistachio. But most people with a pistachio allergy don’t get away with tolerating cashew. There are obviously exceptions, but usually a person has cashew and pistachio allergies.

There are other things in this anacardiaceae family, such as mango. But the fruit of the mango is not cross-reactive with the nut of the cashew, so there usually isn’t a problem there, they just happen to be in the same family. There isn’t really a homologous protein in the flesh of the mango. That’s typically not a problem.

Then you mentioned the pink peppercorn, which is not a routine peppercorn. It is in that same family, and there are just a few reports of problems among people with cashew allergy. It’s not a very common food, so I would typically [tell someone with cashew allergy], don’t bother with it.

In the book, you also raise the issue of pectins. This was news to me.

SS: This gets a little more anxiety-provoking, and most people are not going to have a problem. We’ve seen some reports of people with cashew allergy reacting to foods that contain pectin. Pectin is a fruit-derived product, but it may carry some seed protein that cross-reacts with cashew. When there is an issue, it tends to be people with very significant cashew allergy. The average person with cashew allergy is probably never going to have a problem with pectin. But some people who super, exquisitely reactive to cashew might.

The other anxiety-provoking nuance with cashew allergy is citrus seed proteins. Now we don’t typically eat orange or grapefruit seeds, but there are some reports of people reacting when they have eaten them – you probably have to chew them up to some degree. Again, those tend to be people who are exquisitely allergic to cashew. And the reactivity probably has to do with homologous proteins that are in some of the citrus seeds.

Next: Mystery cases; What turns a reaction severe