Q: My family often eats vegan foods, which fit well with our 12-year-old’s dairy allergy. However, when we ate new plant-based burgers made of pea protein recently, our son got hives on his face and a puffy lip. (This got better with Zyrtec.) Besides dairy, our son has allergies to peanuts and lentils. Is it possible he’s also now allergic to peas? Should we be testing?
Dr. Sicherer: From your description, I’ll assume your 12-year-old has been tolerating green peas up until the reaction to the pea protein burger. There are an increasing number of products that use concentrated bean (legume) proteins. Some common types: flours in bread and pasta made with lentil, lupine or chickpea; the use of concentrated soy (soy protein concentrate/isolate) in processed foods; and, as you identify, the use of concentrated pea proteins.
The increasing number of products enriched with pea proteins, including processed meats but also yogurts, cookies, health supplements, and others, are typically using a type of pea known as yellow, dun or field pea.
When evaluating an allergy like this, I think about the knowledge we have and the history of the patient. Based on studies, about 95 percent of people with peanut allergy tolerate other legumes (even though most will have positive skin or blood tests to multiple beans).
However, if a person with peanut allergy had a reaction to other legumes, like lentils in your son’s case, I may become suspicious of other beans that I call “potent” ones. These are: lupine, chickpea, lentil, yellow (dun) pea, green pea and soy. Typically, if there is a bean allergy, we don’t see it as often for other types (black, white, kidney, lima, green, etc.).
Allergist’s Questions to Consider
Additionally, it’s possible to have an allergy to one or more beans without having a peanut allergy. For example, lentil or lupine allergy without peanut or other bean allergies. Or yellow pea allergy without peanut allergy.
I would have a lot of questions to ask: What other beans is your child eating or not eating? How much does he eat, how often and when was the last time? Has he had subtle issues with beans in the past? What was the amount eaten and severity of past legume reactions? The answers would give me clues on how to address this situation. If a child had been having reactions to beans, especially more than one type, I become more suspicious of other types.
A common myth is that allergy is characterized by having reactions to a small, trace amount of a food. However, many people with an allergy may not have symptoms unless they consume relatively large amounts, perhaps beyond a serving size. This is especially evident with bean allergies. With soy allergy, tofu and edamame may be tolerated as an ingredient, but not soy milk or soy protein concentrate. Or lentils on a salad may be tolerated but lentil soup is not, or separate beans are tolerated but a bean-based pasta is not.
Much Pea Protein in a Burger
So a child who has never had issues with green peas in peas and carrots, peas in rice, or as a side dish may have symptoms from pea soup or pea protein in a burger. In the latter, the amount of protein ingested is much higher. In fact, many of the products with yellow pea protein as a key ingredient are aiming to increase the protein content. The products may state pea protein, pea protein isolate, pea fiber, hydrolyzed pea protein, etc. These are all examples where more concentrated amounts of the protein might cause the problem.
Your allergist may indeed wish to confirm the burger reaction with a skin test to yellow pea. Assuming pea is the culprit, the question may arise as to whether peas should be avoided entirely or allowed in previously tolerated forms and amounts, and whether other beans are a concern.
This discussion typically considers the past history of the patient, the severity of the reaction, motivation to maintain the food in the diet in tolerated forms, and risks of complete elimination (social, nutritional, and possibly allergic). In some cases, medically supervised oral food challenges may be needed.
Dr. Scott Sicherer is a practicing allergist, clinical researcher and professor of pediatrics. He is Director of the Jaffe Food Allergy Institute and Chief of Pediatric Allergy and Immunology at the Icahn School of Medicine at Mount Sinai in New York. He’s also the author of Food Allergies: A Complete Guide for Eating When Your Life Depends On It.Submit a Question View all posts by this medical expert.