Food sensitivities are common in young children. But MPR's medical analyst Dr. Jon Hallberg said that doesn't always mean children will suffer from food allergies for their entire lives.
Hallberg, a physician in family medicine at the University of Minnesota and medical director of the Mill City Clinic, regularly fields questions about children's medical care on MPR's All Things Considered.
Kelsey Dilts McGregor, an associate producer with MPR's Morning Edition, recently gave her 18-month-old son a peanut butter and jelly sandwich. He immediately broke out in hives, and was later diagnosed with a peanut allergy.
All Things Considered Host Tom Crann: Does that sound fairly common, a quick reaction like that?
Dr. Jon Hallberg: Yeah, with young kids with food allergies, most of the time they're diagnosed before a kid hits two years of age. In food allergies, the reaction occurs within seconds to certainly within about two hours.
Crann: What do we know about allergies, especially food allergies in kids?
Hallberg: You'd think we know a lot, but actually we don't know a lot. In the sense that if I do research about it and I look it up as I did for this conversation, one of the first thing that's mentioned is we don't know exactly why the immune system goes haywire this way. For some reason, there's a protein or something with the food that's recognized as being foreign or dangerous, so the body is responding to it in an inappropriate way.
Crann: How do doctors determine whether a child has a food allergy or not?
Hallberg: Most of the time it's exactly like Kelsey's story, with a child who's had a reaction. This is not just a little irritation around the mouth, this is hives, so we know that there's an allergy going on. To further confirm that, almost always, a child will go to an allergist who will then do one or maybe two kinds of testing. They might do a skin testing in some cases, and then most certainly, and it certainly sounds like this was the case, a blood test to see if there's an antibody called IgE, against peanuts, for example.
Crann: Are kids more susceptible to this? Are we hearing about it more? Are we diagnosing it more? What's going on?
Hallberg: I think it's probably a little bit of all of that. About a third of parents of young children think their kids might have some kind of a food reaction. And thank goodness that it only turns out that maybe 5 to 10 percent of kids actually have a true food allergy. Otherwise it's more of a reaction to tomatoes, for example, or eggs, and not a real allergy.
But I think there is a sensitivity where parents in general are much more cautious with their kids and observing things. Maybe if you had five, six, seven kids you just might not notice some of the little things that are going on. Now we're just very attentive.
Crann: That said, there are more severe allergies, some of which could be life threatening. And then there are sort of nuisance allergies, just diversions or sensitivities. Tell us what the difference is.
Hallberg: I think of things as being sort of a spectrum. And maybe it's a spectrum with a box. And in the box you've got just sort of reactions to foods, it makes your tummy a little upset or doesn't settle real well with you. Caffeine can do that with kids or tomatoes, for example.
And then you're talking hypersensitivity and that can be interchanged with the word allergy. The trouble is we don't know where a kid is going to be on that spectrum. It might be really mild, maybe just hives and that's where it ends. But it can be life-threatening and anaphylactic: blood pressure drops, and pulse increases and breathing tubes kind of close up. A person in that case, a child in that case, has to get some epinephrine, frankly, to stay alive.
Crann: And that's an EpiPen that parents would have to carry around?
Hallberg: Yeah, that people often hear about that the school nurse might have, and you might carry in your purse or keep one in your car. People have these all over the place just in case this were to happen. It's a real big spectrum, and that's part of the frustration. We don't know how to measure where a kid might go with a reaction that starts off pretty strong to begin with.
Crann: Do kids actually grow out of these allergies?
Hallberg: That's the good news. Most kids do grow out of food allergies. Among the most common things would be cow's milk, or hen's eggs, chicken eggs. Those allergies tend to outgrow as kids get into adolescence. Things like peanuts or tree nuts, fish or shellfish, are a little harder to outgrow.
Crann: In the end, what would you like parents to know about these issues of food allergies for kids?
Hallberg: If parents are doing their jobs and they're observing their little ones and there's something that's going on that doesn't look too severe, knowing that it's probably not a big deal, it's worth bringing up to your child's healthcare provider. But if it's anything like hives or something severe that absolutely needs immediate attention and then also follow up with an allergist.
Interview transcribed and edited by MPR reporter Jon Collins.