Dr. Stephen Dinetz, MD, pediatric allergist at Nemours Children’s Hospital, talks about the Hygiene Hypothesis and how we could have become too clean during the COVID-19 pandemic. Dinetz also discusses the idea of kids being kids and sometimes being over clean is actually a bad thing.
Interview conducted by Ivanhoe Broadcast News in June 2022.
Why don’t you start with just some basic questions about allergies for our viewers?
DINETZ: What we’re seeing right now is definitely there is an uptick in both food and environmental allergies. Now, the exact reasons for this – not really clear. We don’t have any proven things, but there are a lot of hypotheses out there that are suggestive of why we’re seeing this sort of explosion in not only the adult population, but more so in the pediatric population.
How much of an uptick?
DINETZ: Well, right now what we’re seeing is about 2 to 6% of actual – as far as food allergies in the childhood population. About 25% of people in general report food allergy at some point in their lifetime. Unfortunately, food allergy is misunderstood and some things that are not food allergy do get labeled as food allergy. And, you know, I feel that it’s very important for families to have an evaluation if they suspect that their child has a food allergy by somebody who’s like a board-certified allergy immunologist to kind of get to the bottom is this food intolerance, this lactose intolerance, is this actually a food allergy? That way, the treatment and the care for the child specifically can be the best it can be, because there’s nothing worse than living in fear of food allergies or other allergies and kind of tiptoeing around when your child is actually not allergic to something.
You talked about intolerance and allergy to parents. It might look the same, what is the difference there?
DINETZ: And it can even look the same to physicians, too the definition of food allergy. The allergist uses that it’s an Ige or an immunologic, specifically one part of the immune system that has a reaction to a protein that’s in the food. And this reaction can be life threatening. It’s very quick onset, severe, it’s reproducible, whereas food intolerance could be a reaction to a food. But it may not happen all the time. Or it may be, you know, you have gas or you have other symptoms that don’t quite fit with the allergic part of the immune system.
So what does it look like for parents? What are the symptoms?
DINETZ: So quite frequently what you’ll see is hives or urticaria. You may have lip swelling, throat swelling, lightheadedness because of a drop of blood pressure, vomiting, diarrhea, and usually it’s very quick onset. So child will ingest the food and then within minutes have some sort of reaction.
What is the testing involved then?
DINETZ: So the most accurate way to test is actually for the child to eat the food and then have the reaction. Although this can be very scary for me, the most important and the most accurate way to get to the root of what’s going on with a child is taking a very detailed history from that. You can really discern what’s going on with the child. We do have other testing methods, blood testing and skin testing. However, there are accuracy, you know, issues. They’re not foolproof. It’s not like Star Trek where you just use the little computer thing and out comes your list of what you’re allergic to. Again, the most accurate way is listening to the patient, their family, finding out what happens when, what’s the timeline, what are the details of what happens with the food and then with other testing by blood or skin testing methods? Putting that whole picture together is really how you get to the root of what’s going on.
If a child is found to have food allergies, Doctor, there – is there a cure, or what do parents have to do?
DINETZ: I really wish there was a cure. Right now, avoidance is really the hallmark. There are some patients that undergo food immunotherapy, although this is mostly kind of in the experimental phase. There has been one FDA-approved product for peanut, but it’s not a curative treatment. It more moves the goalposts. And so if your child has a very severe reaction to a food in this case peanut with one peanut, now it’s three or four peanuts before your child has a severe reaction. But you still need to. avoid the food.
Could you explain?
DINETZ: It’s somewhat like that. Now, food, immunotherapy and allergy shots are kind of the same concept. However, with food immunotherapy, we have not gotten to the point where you’re cured after it. You still maintain the allergy to the food and you still need to avoid it. But allergy shots for environmental allergy after 3 to 5 years of treatment, which has been – we’ve been doing allergy shots for over 100 years. And so this is a very tried and tested way of actually retraining the immune system so that instead of an allergic response, now it’s a tolerance response.
What kind of an impact do those treatments have on our kids and kids lives and parents honestly are watching and are worried about their child?
DINETZ: Well, for allergy shots, I mean, it can be life changing. I mean, you can have such an increased quality of life. Your child can, you know, play baseball or do sports or do the activities that they absolutely love and be like a normal kid again for food allergy, Food allergy causes a lot of anxiety for parents. And unfortunately, because we don’t have a tried-and-true cure for food allergy avoidance being the hallmark right now, it can be really scary for families because they have to watch their child like a hawk and make sure that they don’t have any accidents. You may not. You may eat food that doesn’t have any of the main allergens in it, but if it’s cross contaminated, your child can still have a reaction to it.
If you could name some of the top foods that are problematic when it comes to food allergies.
DINETZ: Sure. So the top eight, the classic most common foods are milk, eggs, wheat, soy, peanuts, tree nuts, fish and shellfish. And one food that’s rapidly on the rise right now is sesame. As a lot of people are turning to different cuisines, experimenting with new foods. Sesame is now the up-and-coming allergy. So some people are saying, well, we’ll make it the top nine.
So is that sesame seed or sesame oil?
DINETZ: Well, that’s a very tricky question. So with sesame, it’s the seed, it’s the protein. So the sesame oil, it depends on how it’s made. So in most cooking oils, if it’s a refined cooking oil, they go through a process where the protein part of the sesame or peanut or whatever is used is actually removed. And it’s just the fat and allergens are always in the protein. And so, for example, if you wanted to go to a certain restaurant that has, you know, a cow as its sponsor, they fry everything in peanut oil. And a lot of families come to me and they think, oh, we can’t have – it’s our favorite fast-food restaurant? But they use refined peanut oil, and so it’s safe to – for your peanut-allergic child.
What kind of food? You talked about new cuisine when you’re talking about a sesame seed. What kind of food is on the rise that…
DINETZ: So the one that I’ve seen most commonly is hummus. So hummus has tahini in it, which is made from sesame seeds. And that is very delicious. But it can be a problem for children that are sensitive to the sesame seed portion of it.
Can you tell me what the hygiene hypothesis is?
DINETZ: Sure. So the hygiene hypothesis is the theory that with cleaner environments, antibacterial soaps, that we are not getting exposed to the appropriate levels of allergens in the environment. And because of that, that’s leading to a higher level of allergic sensitization in our kids.
And what do we see when we talk about allergic sensitive sensitization? What does that mean?
DINETZ: So, for example, me as a kid growing up, was you go play outside, come in before it gets dark. Drink from the, you know, the garden hose, you know. You ate Dirt. And you’re happy. And, you know, you just lived your best life. Now, you know, you’ve got antibacterial soap, you’ve got dishwashers, you’ve got all these things. Even the, you know, infants, they have the bottle, sterilizers and whatnot. And so it’s a very antiseptic environment and with the hygiene hypothesis. The basic premise is that just like you have to get educated in school as a child and you’re growing up, so does your immune system. And having that exposure to all of these different allergens or germs or whatnot in the environment prepares your body, educates your immune system. And so in so doing, that is a protective feature to prevent the development of allergies and allergic disease.
Are we way too clean?
DINETZ: I definitely think it’s a valid concern. Now, I have not seen any published data that says that there’s absolutely a increase just because of increased cleaning practices. But again, I think it’s how you clean and what you let your child interact with. And so there’s nothing wrong with using the dishwasher. There’s nothing wrong with keeping a clean house. But at the same time, your child should be doing normal kid stuff, going out there and, you know, living their best life.
So how do you draw that fine line as a parent? You know, you want everything to be clean for your child. You certainly want to avoid COVID, but you don’t want to overdo it. Where’s the line in between?
DINETZ: If I knew the exact answer, I’d be a very rich person. There’s – really what I tell families is just use your best judgment because that fine balance that you have, you also as a parent have to make sure that you feel OK with what your child’s doing. And if, for you, you’re too nervous or anxious about the risk level with your child, then that’s also an unhealthy situation. So we have to find a balance between letting your child do normal stuff. Your overall health and well-being. And also, you know, making sure that you’re doing everything for your child so that they live a healthy and happy life.
What’s going on in the system that is preventing kids from developing that tolerance to bacteria?
DINETZ: Right. So when the immune system sees different viruses, bacteria, it learns how to kill them and develop an immunity for the child. And in going through that process, the body stays down a certain immune pathway. When that is taken away and you have very low amounts of allergens introduced to the body, the body can go down a different pathway and that’s the allergy pathway when there’s just this rare exposure and that rare exposure can lead to allergic sensitization and then from there development of allergies. So, you know, the model, like I was saying earlier, of just going around, playing in the dirt and doing that kind of stuff that can actually be protective for your child. And so, you know, you still want to keep things clean, but you also want to make sure that your child is getting appropriately exposed to just life in general. So that way they can have the normal reactions to things in their environment.
The hygiene hypothesis doesn’t increase food allergies, does it?
DINETZ: Well, it’s really both. It’s really both because there’s actually a study that compared homes with dishwashers to homes where you hand-wash dishes. And they actually saw in the study that the homes that hand-washed, there was less incidence of food allergy. And so through micro exposures, repeatedly of certain food proteins on plates, cups, bottles, those children actually were protected against food allergies, whereas the dishwasher, home, everything was sterilized. And so those exposures weren’t happening. And so then that led to down the road those children developing food allergies.
Is there anything in particular that parents should clean with? Is good old soap and water. Better than the heavy antibacterial that we’ve been using or is it up to your preference,
DINETZ: I honestly have not seen any studies that say one thing’s better than the other. I just say, use what you’re comfortable with, what you like. But again, let kids be kids.
END OF INTERVIEW
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