Did you know that 88% of schools enroll at least one student with a food allergy? It’s estimated that 8% of the child population, or 1 in 13, have food allergies – that’s 6 million children! What’s more, approximately 30% of children with food allergies are allergic to more than one food.

What is a Food Allergy?

Let’s take it a step back. A food allergy is a medical condition where exposure to a food abnormally triggers a harmful reaction in the immune system. The immune system attacks the protein within the food, and these proteins triggering the reaction are called allergens. For example, milk contains two main categories of protein: casein and whey. Casein is found in the solid portion (the milk curd), while whey is found in the liquid portion.

While there are over 170 types of food known to cause food allergies, eight are by far the most common, accounting for a staggering 90% of all food allergies.

Read below to discover the eight most common food allergens, and examples of products that may include them. Many of these products are likely used in your school’s nutrition program.

  • Found in: cereals, granola bars, glazes, marinades, nougat, sauces
  • Almonds, cashews, pistachios, chestnuts, coconuts, hazelnuts, walnuts, pecans, macadamia nuts, and more
  • Found in: barbecue sauce, salad dressing, pie crust, pesto, chicken breading, honey
  • Found in: cream, butter, cheese, sour cream, ice cream, pudding, yogurt
  • Found in: baked goods, breading on meat, ice cream, marshmallows, mayonnaise, pasta, pretzels, sauces
  • Found in: edamame, miso, processed meats (like hot dogs), Worcestershire sauce
  • Found in: bread, muffins, pastries, donuts, pancakes, waffles, crackers, chips, pasta, soup, cakes, cookies
  • All finned fish: catfish, cod, haddock, pollock, salmon, tilapia, tuna
  • Found in: fish sticks and fillets, Caesar salad and Caesar dressing, Worcestershire sauce, bouillabaisse, imitation fish or shellfish
  • Crustaceans – crab, lobster, shrimp; and mollusks – clams, mussels, oysters
  • Found in: egg rolls, fish sticks or fillets, fish stock, gumbo, jambalaya, paella, seafood flavoring, Worcestershire sauce


What are the symptoms of an allergic reaction? Allergic symptoms range widely depending on the severity, making them difficult to detect. These symptoms can range anywhere from a mild annoyance to a life-threatening condition, known as anaphylaxis. Symptoms can occur anytime between a few minutes to two hours after ingestion.

  • Hives
  • Rash
  • Flushed skin
  • Swelling
    • Face, tongue, lip, throat, and vocal cords
  • Tingling or itching in the mouth
  • Vomiting
  • Diarrhea
  • Abdominal cramps
  • Coughing or wheezing
  • Dizziness
  • Lightheadedness
  • Difficulty breathing
  • Unconsciousness
  • Anaphylaxis – a serious allergic reaction that can cause death

Rise in Allergen Prevalence

The Centers for Disease Control and Prevention reports food allergies have increased an alarming 50% between 1997 and 2011. What could be the reason behind this?

One possibility is a theory called the “hygiene hypothesis”. Do you, or someone you know, constantly use hand sanitizer? The hygiene hypothesis suggests our lives nowadays are too clean – limiting kid’s exposure to germs. This means with less exposure, the immune system is not as well-trained to understand the difference between harmless and harmful irritants.

The hygiene hypothesis is supported by studies which have shown people who live on farms develop less allergic diseases. This theory suggests farm animals increase the exposure to germs and endotoxins (germ components). Endotoxins stimulate the immune response, and decrease allergic inflammation.


Other studies suggest that increased antibiotic use is the reason for the rise in allergies. These researchers note that early use of antibiotics can change one’s bacterial flora (harmless bacteria living in the body), which impacts the development of allergic diseases. An increase of acetaminophen, also known as Tylenol, may also increase the likelihood of developing allergies.

The Unknown

There are quite a few factors that make it difficult to determine why food allergies have increased so much in recent years. According to Dr. Virginia Stalling, a board-certified nutrition pediatrician in at The Children’s Hospital of Philadelphia, one issue is an overlap in symptoms. For example: a child exposed to milk for the first time could experience abdominal cramps or other gastrointestinal symptoms. This makes it hard for the parent to determine whether the child has a milk allergy, or if their child is lactose intolerant.

“We do not have an optimal diagnostic tool,” said Stallings. “There isn’t one skin test or blood test that can accurately determine whether a person has an allergy to a specific food.”

What Can We Do?

As there are no cures for food allergies, the only way to prevent them is to strictly avoid the food allergen. That being said, it’s highly important to utilize strategies and techniques to help manage them in your school nutrition program. For example, menu planning software marks allergens at an ingredient level, which tracks them all the way through the recipe, menu, and into the menu cycle.

Has your school faced challenges regarding food allergens? Tell us your stories in the comments section below. Be on the lookout for the second part of this blog series which will encompass allergy management in your nutrition program.