Foods can cause many adverse reactions; here’s how to know if it’s a food allergy.
As an allergist, I frequently am asked to evaluate children for suspected food allergy. A few years ago, I was personally faced with this question when my daughter developed acute hives after her first taste of peanut butter. Truly, I didn’t want to see what was before my eyes, and I questioned myself. One tiny bite of peanut butter and she had immediate swelling of her lips, a line of hives across her face and neck and she was scratching at her tongue while crying. This was the real deal.
But sometimes, food allergies are not so obvious. Food allergies are often misunderstood.
An allergy to a food has a strict definition: a specific IgE-mediated reaction to a food substance. Twenty-five percent of the general population has reported an adverse reaction to foods, with most occurring in infancy and childhood. People can experience a variety of adverse reactions to food, such as food intolerance and food poisoning, which makes true food allergy one of many possibilities. Although adverse reactions to foods are much more common, food allergy is rare.
The prevalence of food allergy to peanuts and tree nuts, however, is rising. Peanut allergy is the most common cause of fatal food-induced anaphylaxis. Those at highest risk are adolescents with asthma. The rise in food allergies has resulted in more awareness, and you probably now know someone with a food allergy or have had changes implemented in schools or work places.
Sensitivity to food allergens can wane throughout childhood and most children will develop tolerance to foods such as cow’s milk, egg and wheat. More tenacious allergies, such as to peanuts, tree nuts and shellfish, are more often lifelong, with only about 20 percent of individuals outgrowing allergies to these substances.
Food-allergy reactions are typically described as immediate, meaning they occur in seconds to minutes after ingestion. Symptoms often include hives, swelling of lips, vomiting, diarrhea, wheezing, decreased blood pressure and/or swelling of the throat. It is critical to avoid the food to which a person is allergic. In case of accidental ingestion, it is paramount to treat food allergies quickly.
Many studies have shown that the true prevalence of food allergy is lower than the number of suspected food allergies. Unnecessary dietary restriction can have a striking impact on quality of life and on an individual’s nutritional status. Suspected food allergies should, therefore, be evaluated by a board-certified allergist/immunologist.
This post was written by Stacy Dorris, M.D., a pediatric allergy and immunology specialist at the Monroe Carell Jr. Children’s Hospital at Vanderbilt.
Dealing with allergies after diagnosed
For children just diagnosed with serious food allergies, navigating class parties or school lunches may seem impossible. Read this interview with Stacy Dorris, M.D., on how to proactively manage food allergies at school.