In our first post on what you need to know about kids and food allergies, we discussed what a food allergy reaction may look like, which foods are the most common culprits and some general advice on how to treat a reaction. I also began describing an allergic reaction scenario that happened to my friend’s 10-year-old son. He experienced hives and swelling about half an hour after eating take-out Chinese food and just after playing in the grass. His sudden symptoms led his parents to take him to the hospital. We ended up with the question: Was this 10-year-old’s reaction an allergic reaction to the food or to the grass?
Before we dive back into his story, let’s discuss when to bring your child to an allergist instead of your pediatrician or the ER, and how allergists diagnose allergies in kids.
When should I bring my kid to an allergist?
If your child is currently experiencing symptoms, immediately contact your pediatrician or allergist if you have one. If your child is experiencing a more severe reaction, go straight to the emergency room. Call 911 for an ambulance if the reaction seems dangerous so that the care for your child starts immediately while on the way to the hospital. If your child isn’t currently having a reaction or seems to be having a mild one, you can consult your pediatrician or allergist.
The folks in the ER have a tough job. They receive patients in acute distress and must diagnose and treat them in the moment. ER care providers must assume every reaction is potentially life-threatening and therefore need to prioritize managing the symptoms rather than assessing the triggers of the symptoms. Unfortunately, as few as 20 percent of those diagnosed with a anaphylaxis in the ER receive a prescription for Epinephrine. With such low numbers, the concern is that families are not following up with specialists to ensure the best course to navigate food allergies. Ideally, you should test for your kid’s allergies with an allergist before severe symptoms occur.
Allergists are able to help families avoid the right foods, while keeping safe foods in the diet, which may help prevent the development of new allergies. Once children walk into the door of an allergist, they are in a much safer space. Allergists have the luxury of stepping back and really questioning whether a severe reaction was truly triggered by foods. We can often deduce that there was no food reaction and safely reintroduce the foods back into your kid’s diet. This is essential, as some children may develop a food allergy precisely because the food was erroneously eliminated.
Besides the oral challenge mentioned in our last blog, an exhaustive history of the reaction and diet can be far more accurate than any testing. Remember, food allergies will happen every single time the food is ingested, and usually immediately. If you’re worried your child has a food allergy, but they have recently tolerated the food, it is unlikely to be a true allergy. Once we develop an allergy to a food, medication or insect, we will react every single time.
How do allergists diagnose allergies in kids?
A detailed history of reactions gives allergists clues as to which foods should be tested. If you think your child may be allergic to a specific food, keep a journal of what your child is eating, the time of day and any reactions. We try to avoid allergy panels, especially, when history indicates a food is safe, since panels can lead to false positives. Testing can be by a skin prick test with a safe dilute sample of the protein, or by measuring allergy antibodies in the blood. A positive skin test elicits a small hive at the site of the scratch within minutes, which will fade soon after the visit. We avoid testing too many foods as the false positive rate is around 50 percent for skin tests. Overtesting foods that history indicates are tolerated can do more harm than good. If your child tests positive to a food that had nothing to do with a reaction and has been able to tolerate the food in the past, your allergist may recommend that they keep eating the food. Especially in younger children, avoidance of a safe food may trigger a true reaction.
How can I tell the difference between a food and an environmental allergy?
As much as 50 to 60 percent of the time patients suffer from hives or swelling, the symptoms are actually from exposure to an infection. The antibodies that are created to defend our body sometimes also trigger our allergic immune system. Since kids can usually be an hour from their last snack or meal, we’re often tempted to blame foods for non-allergic reactions.
Let’s get back to my friend’s 10-year-old, who experienced a reaction that may have been environmentally- or food-triggered. In his case, he ate Chinese food at his grandparents’ house from a restaurant he had no issues with for years before, including the day before. Possible high-risk ingredients in the food were peanut, cashews and shrimp. My friend’s son had eaten all these foods before (and frequently) without problems. The symptoms started 30 minutes after his meal, while he was playing in the grass on a pollen-crazed day. His symptoms did not progress past eye swelling and hives which lasted at most through the next day. He had a couple doses of Benadryl and then Zyrtec twice daily and did not require epinephrine. The ER did send him home with a prescription for the family to fill, which too often does not happen.
My friend’s 10-year-old had negative allergy testing for peanuts, tree nuts and shrimp. All the foods were gradually reintroduced back into the diet per a dosing schedule I recommended to his parents, and he had no reactions. He was diagnosed with idiopathic anaphylaxis, which is a fancy way of saying he had a possible reaction without known cause. More likely, my friend’s son experienced hives and swelling from an infection or environmental pollen exposure.
What is the prognosis for food allergies?
Up to 80 percent of children outgrow milk, egg, soy and wheat allergy, although it may take several years. Peanuts, tree nuts and seafoods are not commonly outgrown: Only 20 percent of those with nut or seafood allergies will be able to tolerate these foods again. With these allergens, strict avoidance gives the best chance to outgrow allergies. In the future, treatments that safely teach the body to tolerate these foods may be developed.
As with most aspects of your family’s physical health, prevention is preferred over treatment. Setting up an appointment with an allergist to safely conduct allergic reaction testing is an important step in preventing severe allergic reactions for your kids, and will also allow you to ask in-depth questions about your kid’s sensitivity to foods, an ideal diet for living with food allergies and your child’s chances of outgrowing a certain allergy. In the next post, I’ll discuss current theories on how food allergies develop and how to prevent food allergies.
Dr. Steve Handoyo is a Clinical Associate of Pediatric Allergy and Immunology at the University of Chicago. For more information or to schedule an appointment, please visit his University of Chicago page or call 773.702.6169.