Food allergies are a growing concern for many families, especially as children enter school, attend social events, and are exposed to a wider variety of foods.
Vinh T. Nguyen, MD, FAAP, a pediatric allergist and immunologist at Loma Linda University Children's Hospital, sheds light on how food allergies are diagnosed, managed, and sometimes even outgrown.
Nguyen treats children up to age 18 for a range of allergic conditions, including allergic rhinitis, eczema, asthma, food allergies, and even immune deficiencies. He says skin prick testing remains the best screening procedure for food allergies.
"Skin testing tends to be more reliable and accurate than blood testing," said Nguyen. "Blood tests can have false positives, so we typically start with skin tests unless there's a reason we can't."
While many parents worry their child might suddenly develop a food allergy later in life, Nguyen says that's rare.
"The vast majority develop in early childhood, typically when solids are first introduced," he said. "The earlier you introduce foods, the less likely a child is to develop an allergy."
According to Nguyen, hives are the most common initial signs of a food allergy reaction. "It's usually the first indicator," he said. "In cases of anaphylaxis, a severe, potentially life-threatening allergic reaction, you'll often see a combination of symptoms like vomiting, wheezing, or swelling alongside hives. You need at least two organ systems to classify it as anaphylaxis."
In some cases, allergists will perform an oral food challenge in the clinical setting, a supervised process where small, increasing amounts of a suspected allergen are given to a patient to assess tolerance.
Nguyen says the best way to prevent accidental exposure is by being proactive.
"Most accidental ingestions happen because someone didn't know the child had a food allergy," he said. "So, when you're going to a restaurant, a playdate, or any place with food, let people know. And always carry your EpiPen and medications, just in case."
Can Food Allergies Be Outgrown? Some can. "Egg and milk allergies are outgrown most frequently, around 70 to 80% of kids will outgrow those. But allergies to peanuts, tree nuts, fish, and shellfish are much more persistent, with only about a 15 percent chance of resolution into adulthood."
He emphasized that any effort to reintroduce an allergenic food should only be done under a doctor's supervision. "The safest place to do that is always in a clinic.
Parents often ask whether foods like exotic fruits or rare grains might trigger allergic reactions. While not impossible, Nguyen says most food allergies fall into nine categories. Peanuts, tree nuts, fish, shellfish, eggs, milk, soy, wheat, and sesame.
These are the foods responsible for the vast majority of allergic reactions, and they're required to be labeled on packaged foods in the U.S.
For concerned parents navigating a food allergy diagnosis, Nguyen's advice is simple: build a strong partnership with your child's allergist, communicate openly with others, and never leave home without emergency medications.
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