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Food Allergy Guide: The 9 Most Troublesome Foods

Written by Andrew Le, MD

UpdatedNovember 18, 2023

According to the Centers for Disease Control & Prevention (CDC), there was a 50% increase in the occurrence of food allergies in children from 1997 to 2011. This necessitates a demand for more allergen-free options, improved labeling, and heightened education for both healthcare professionals and the general public.

Additionally, a recent study revealed that 40% of children with food allergies in the US had to seek emergency treatment. This underscores the critical need for effective allergy management and immediate access to medical care.

Given these challenges, many individuals find themselves uncertain about safely enjoying their favorite dishes. In this guide, we'll delve into the nine major food allergens, providing you with the knowledge needed to make informed choices. Let's get started!

🔑 Key Takeaways

  • There are nine major food allergens recognized in the US, including sesame which was added in 2021.
  • Milk allergy is prevalent among children, affecting 1.9% of US children. Casein and whey proteins in cow's milk are common triggers.
  • Eggs are a common allergen, with 1 in 100 children in the US affected. Allergic reactions are primarily triggered by proteins in the egg white.
  • Mollusks have not been designated as major allergens by the USFDA.
  • Tree nut allergies impact over 2% of children and can continue into adulthood. They are a common cause of anaphylactic events.
  • Some individuals with wheat allergies may experience symptoms only when they exercise shortly after consuming wheat.
  • Reporting allergic reactions and labeling issues to the FDA is essential for ensuring food safety for everyone.

Understanding Food Allergy

A food allergy occurs when someone consumes, comes into contact with, or inhales a specific protein found in food known as an allergen. These allergens are usually glycoproteins that easily dissolve in water. They're resilient and can cross the protective lining of the intestine.

As a response, the immune system generates a specialized type of antibody called immunoglobulin E (IgE) in reaction to this allergen. These IgE antibodies circulate in the bloodstream and adhere to two types of cells within the immune system.

Subsequently, when food allergens breach the body's defensive barriers and reach the specific antibodies on cells, they prompt the release of substances that induce muscle contraction, widen blood vessels, and stimulate excess mucus production. This cascade of events leads to immediate food allergy symptoms.

Now that we understand how food allergies manifest, let's explore some common foods that can trigger these reactions.

9 Allergenic Foods to Avoid

In 2004, the Food Allergen Labeling and Consumer Protection Act (FALCPA) officially designated eight foods listed below as primary food allergens. Recently, on April 23, 2021, the Food Allergy Safety, Treatment, Education, and Research (FASTER) Act was enacted, adding sesame as the ninth major food allergen recognized in the US.

1. Milk

Milk allergy, often referred to as cow's milk allergy, is highly prevalent among children. Approximately 1.9% of children in the US experience this allergy. Moreover, it stands as one of the most widespread food allergies on a global scale.

Cow's milk contains two primary proteins that can lead to an allergic response - casein and whey proteins. These milk proteins are commonly found in various dairy products such as:

  • Whole milk, low-fat milk, skim milk, and buttermilk
  • Butter
  • Yogurt
  • Ice cream
  • Gelato
  • Cheese
  • Cheese-containing items
  • Half and half

Identifying milk in processed foods, such as baked goods and processed meats, can be more challenging. Concealed sources of milk include:

  • Whey
  • Casein and caseinates
  • Ingredients with the "lact" prefix like lactalbumin, lactalbumin phosphate, lactate solids, lactitol monohydrate, lactoglobulin, lactose, and lactulose.
  • Candies like chocolate, nougat, and caramel
  • Flavoring (natural flavoring, caramel flavoring)
  • High protein flour
  • Hydrolysates

The following milk derivatives are generally considered safe for most individuals with a milk allergy, but it's important to consult your doctor before consumption:

2. Eggs

A survey was conducted between October 2015 and September 2016. It revealed that nearly 1 in 100 children in the US have an egg allergy. Interestingly, the highest prevalence was observed among the youngest age group.

The five primary components responsible for egg allergies are primarily found in the egg white. These include:

  • Ovomucoid
  • Ovalbumin
  • Ovotransferrin
  • Egg White Lysozyme
  • Ovomucin

While ovalbumin is the prevalent protein in egg white, it's ovomucoid that's seen as the dominant allergen.

To steer clear of eggs, avoid foods with these ingredients:

  • Albumin (also spelled albumen)
  • Apovitellin
  • Avidin globulin
  • Egg (dried, powdered, solids, white, yolk)
  • Eggnog
  • Lysozyme
  • Mayonnaise
  • Meringue (meringue powder)
  • Ovalbumin
  • Ovomucoid
  • Ovomucin
  • Ovovitellin
  • Surimi
  • Vitellin

Additionally, eggs are sometimes found in:

  • Baked goods (consult your allergist, as some people can tolerate them)
  • Pancakes and waffles
  • Egg-washed bread
  • Cake decorations or fillings ( buttercream, frosting, mousse)
  • Chips
  • Crackers
  • Fat substitutes made with egg
  • Hollandaise sauce
  • Ice cream, custard, sorbet
  • Lecithin
  • Marzipan
  • Marshmallows
  • Nougat
  • Certain pasta varieties
  • Some pretzels (they might be covered in egg wash before being salted)
  • Salad dressings
  • Soufflé
  • Special coffee and bar drinks (eggs can be used in the foam or topping)
  • Tortillas

While allergens aren't always present, egg protein can show up unexpectedly. It's best to read food labels and inquire about ingredients if you're ever unsure about a particular item.

🩺 Doctor’s Note

Some vaccines may contain egg proteins. While most are safe for those with egg allergy, a few precautions may be necessary. It's always wise to consult your doctor, especially if there are any concerns.

3. Fish

Fish allergy is less common in the US, affecting 0.4% of the total population. However, it can become a lifelong condition as 40% of individuals with a fish allergy have their first reaction as adults.

The primary allergenic substance in fish is a natural muscle protein known as parvalbumin. There is also some indication of allergic responses to other proteins found in fish, such as collagen.

There are over 20,000 species of fish. While this isn't an exhaustive list, allergic reactions have been frequently reported for:

  • Anchovies
  • Bass
  • Catfish
  • Cod
  • Flounder
  • Grouper
  • Haddock
  • Hake
  • Halibut
  • Herring
  • Mahi mahi
  • Perch
  • Pike
  • Pollock
  • Salmon
  • Scrod
  • Sole
  • Snapper
  • Swordfish
  • Tilapia
  • Trout
  • Tuna

Unexpected sources of fish may include:

  • Barbecue sauce
  • Bouillabaisse
  • Nam pla (Thai fish sauce)
  • Caesar salad and Caesar dressing
  • Caponata, a Sicilian eggplant relish
  • Imitation or artificial fish (like surimi, also known as "sea legs" or "sea sticks")
  • Worcestershire sauce
  • Kimchi made with fish sauce

Fish allergens may not always be present in these foods and products, but they can sometimes be unexpectedly included. Therefore, it's advisable to carefully read food labels and ask questions if you're uncertain about the ingredients in a particular item.

🩺 A Doctor’s Note

Fish allergy is occasionally mistaken for iodine allergy due to the presence of iodine in fish. However, the allergic reaction in individuals with fish allergy is not caused by iodine. Therefore, if you have a fish allergy, there's no need to be concerned about cross-reactions with iodine.

4. Crustacean Shellfish

Tropomyosin is the primary allergen found in shellfish. The term "shellfish" encompasses a wide variety of edible creatures, from crustaceans like crabs or shrimp to mollusks like clams or scallops.

About 14% of individuals with shellfish allergies are sensitive to both crustaceans and mollusks. However, mollusks have not yet been designated as major allergens by the US Food and Drug Administration (USFDA).

Be cautious with foods containing any of these elements:

  • Crab
  • Crawfish (also known as crawdads, crayfish, or ecrevisse)
  • Lobster (includes langouste, langoustine, Moreton bay bugs, scampi, tomalley)
  • Prawns
  • Shrimp (also referred to as crevette or scampi)
  • Krill
  • Barnacle

Your doctor might recommend avoiding mollusks or these ingredients:

  • Abalone
  • Clams (including cherrystone, geoduck, littleneck, pismo, quahog)
  • Cockle
  • Cuttlefish
  • Limpet (also known as lapas or opihi)
  • Mussels
  • Octopus
  • Oysters
  • Periwinkle
  • Sea cucumber
  • Sea urchin
  • Scallops
  • Snails (commonly called escargot)
  • Squid (sometimes labeled as calamari)
  • Whelk (or Turban shell)

Shellfish can sometimes be present in the following:

  • Cuttlefish ink
  • Glucosamine
  • Fish stock
  • Seafood flavoring (like crab or clam extract)
  • Fish stock or fish sauce (which may be made from krill)
  • Surimi
  • Bouillabaisse

It’s worth noting that the federal government does not mandate full disclosure of mollusks on product labels.

🎉 Fun Fact

China is the biggest consumer of seafood, followed by Japan and the US. In 2009, the average American consumed about 15.8 lbs of fish and shellfish per person. Shrimp was the most popular choice, with an average of 4.1 lbs per person.

5. Tree Nuts

Botanically, tree nuts are the seeds of certain fruit-bearing trees. However, they are distinct from seed allergens like sesame, sunflower, poppy, and mustard, as they do not originate from trees.

The six most frequently reported tree nuts among both children and adults are:

  • Walnuts
  • Almonds
  • Hazelnuts
  • Pecans
  • Cashews
  • Pistachios

Below is a compilation of tree nuts acknowledged by the FDA. In FDA-regulated foods, the specific tree nut name must be clearly stated on the label. Always inspect labels, even if your child has consumed the product without issues before.

  • Almond
  • Beech nut
  • Brazil nut
  • Bush nut
  • Butternut
  • Cashew
  • Chestnut (Chinese, American, European, Seguin)
  • Chinquapin
  • Filbert
  • Gingko nut
  • Hazelnut
  • Hickory nut
  • Lichee nut
  • Macadamia nut
  • Pecan
  • Pili nut
  • Pine nut
  • Pinon nut
  • Pistachio
  • Walnut (English, Persian, Black, Japanese, California)

In addition, nuts can also be found in:

  • Artificial flavoring
  • Baked goods
  • Desserts
  • Mortadella
  • Natural flavoring
  • Nougat
  • Pesto
  • Trail mix
  • Vegetable oils

Studies indicate that allergies to tree nuts impact over 2% of children, and a many of them will continue to have these allergies into adulthood.

💡 Did You Know?

Up to one-third of anaphylactic events triggered by food allergens are associated with the consumption of tree nuts.

6. Peanuts

The allergy to peanuts is caused by proteins with low molecular weight. These proteins are able to withstand heat, proteases, and denaturants. Currently, there are 16 officially recognized allergenic proteins in peanuts.

While 30% of peanut-allergic individuals may also have a tree nut allergy, being allergic to tree nuts does not automatically imply an allergy to peanuts. Peanuts grow below the ground and are part of the legume group, setting them apart from nuts that grow on trees.

Peanut allergy is usually lifelong and potentially fatal. To effectively manage your peanut allergy, it's crucial to steer clear of the following foods containing peanuts. This includes:

  • Arachis oil (another term for peanut oil)
  • Artificial nuts
  • Beer nuts
  • Cold-pressed, expelled, or extruded peanut oil
  • Ground nuts
  • Lupin (or lupine)—a common gluten-free flour substitute, but it may cross-react with peanuts, unlike other legumes.
  • Mandelonas (peanuts soaked in almond flavoring)
  • Mixed nuts
  • Monkey nuts
  • Nut meat or nut meal
  • Nut pieces
  • Peanut butter
  • Peanut flour
  • Peanut protein hydrolysate

Highly refined peanut oil isn't mandated to be labeled as an allergen. Research indicates that most people with peanut allergy can safely consume this type of peanut oil. Consult your doctor if you're unsure about highly refined peanut oil.

Peanuts may be unexpectedly present in various products like:

  • African, Asian (particularly Chinese, Indian, Indonesian, Thai, and Vietnamese), and Mexican restaurant fare poses a high risk of cross-contact, even if you order a dish without peanuts.
  • Alternative nut butter like soy nut butter or sunflower seed butter may share equipment with other tree nuts and sometimes peanuts. Contact the manufacturer before consuming these products.
  • Candy, including chocolate treats
  • Chili dishes
  • Egg rolls
  • Enchilada sauce
  • Glazes and marinades
  • Grains like Museli cereal
  • Granola
  • Ice creams
  • Marzipan
  • Nougat
  • Pancakes
  • Various sauces like chili sauce, hot sauce, pesto, gravy, mole sauce, and salad dressing
  • Specialty pizzas
  • Sunflower seeds, commonly handled with the same equipment as peanuts.
  • Sweets such as pudding, cookies, baked goods, pies, and hot chocolate
  • Trail mix
  • Vegetarian food items, especially those marketed as meat substitutes

Recent studies suggest that younger siblings of children with peanut allergies may have an elevated risk of developing the same allergy. Consult your doctor for advice on food allergy testing for siblings.

🎉Fun Fact

In 2020, the FDA approved an oral immunotherapy medication for peanut allergies. This treatment aims to lower the risk of anaphylaxis resulting from unintended peanut exposure. It involves gradually increasing the medication dose, often under the supervision of an allergist, over several months.

7. Wheat

Children are more likely to have a wheat allergy, which can occasionally result in serious reactions. For people who work with wheat a lot, like bakers, breathing in wheat particles over time can cause a type of asthma called baker’s asthma.

Wheat is the most commonly used grain product in the US. To prevent an allergic reaction, it's crucial to steer clear of wheat and foods containing wheat.

Here are some items to avoid:

  • Bread crumbs
  • Bulgur
  • Cereal extract
  • Club wheat
  • Couscous
  • Cracker meal
  • Durum
  • Einkorn
  • Emmer
  • Farina
  • Farro
  • Various types of flour (like all-purpose, bread, cake, durum, enriched, graham, high-gluten, high-protein, instant, pastry, self-rising, soft wheat, steel ground, stone ground, whole wheat)
  • Freekeh
  • Kamut
  • Matzoh or matzoh meal (also spelled as matzo, matzah, or matza)
  • Pasta
  • Seitan
  • Semolina
  • Spelt
  • Sprouted wheat
  • Triticale
  • Vital wheat gluten
  • Various wheat-related parts (like bran, durum, germ, gluten, grass, malt, sprouts, starch)
  • Wheat bran hydrolysate
  • Wheat germ oil
  • Wheat grass
  • Wheat protein isolate
  • Whole wheat berries

Sometimes, wheat can also be found in:

  • Glucose syrup
  • Soy sauce
  • Starch (including gelatinized starch, modified starch, modified food starch, vegetable starch)
  • Surimi
  • Plant-based meat alternatives

Moreover, you might not have anticipated some of the wheat-containing foods below.

  • Ale
  • Asian dishes may use wheat flour shaped to resemble beef, pork, or shrimp.
  • Baked goods
  • Baking mixes
  • Batter-fried foods
  • Beer
  • Breaded foods
  • Breakfast cereals
  • Candy
  • Country-style wreaths are often decorated with wheat products.
  • Crackers
  • Hot dogs
  • Imitation crab meat
  • Ice cream
  • Marinara sauce
  • Personal care items (such as cosmetics or hair products)
  • Play dough or modeling clay
  • Potato chips
  • Processed meats
  • Rice cakes
  • Salad dressings
  • Sauces
  • Sausages
  • Spices
  • Soups
  • Turkey patties

If you have a wheat allergy, there's a chance you might also be allergic to barley, oats, and rye. However, unless you're allergic to grains besides wheat, following a wheat-free diet is generally less restrictive than a gluten-free diet.

💡 Did You Know?

Some people with a wheat allergy may only have symptoms when they exercise shortly after eating wheat. Physical activity can either trigger an allergic reaction or make the immune system's response to a wheat protein worse.

8. Soybeans

For many years, people have relied on soybeans as a valuable food packed with protein, essential fatty acids, minerals, and fibers. However, it is a common food allergen among infants and young children, affecting about 0.4% of infants in the US.

If you're allergic to soy, it's best to steer clear of these food items:

  • Edamame
  • Miso
  • Natto
  • Soy sauce and shoyu sauce
  • Soy-based fiber, flour, grits, nuts, or sprouts
  • Soy-based milk, yogurt, ice cream, or cheese
  • Soy protein
  • Tamari
  • Tempeh
  • Teriyaki sauce
  • Textured vegetable protein (TVP)
  • Tofu

These foods could also potentially contain soy:

  • Baked goods (like bread, cookies, and crackers)
  • Canned broth and soup
  • Canned tuna and meat
  • Cereals
  • Frozen dinners
  • High-protein energy bars and snacks
  • Ice cream
  • Infant formula, baby foods, and cereals
  • Low-fat peanut butter
  • Meat substitutes
  • Processed meats, such as deli meats
  • Salad dressings, mayonnaise, gravy, and sauces
  • Vegetable oil
  • Worcestershire sauce

Below are names that may signify the presence of soy. If you spot these names on an ingredient list, it's advisable to avoid the product.

  • Glycine max
  • Hydrolyzed vegetable protein (HVP)
  • Mono-diglyceride
  • Monosodium glutamate (MSG)

If you come across an unfamiliar ingredient, remember to always conduct thorough research first. You can even reach out to the product's manufacturer via email if you still have uncertainties.

9. Sesame

Sesame allergy is the ninth most prevalent food allergy in both children and adults in the U.S. Based on a thorough population survey, around 0.49% of the U.S. population currently report a sesame allergy, with 0.23% meeting distinct symptom criteria.

Starting from January 1, 2023, it's now mandatory to label sesame allergens on food packages. Avoid foods containing sesame or any of these ingredients:

  • Benne, benne seed, benniseed
  • Gingelly, gingelly oil
  • Gomasio (sesame salt)
  • Halvah
  • Sesame flour
  • Sesame oil
  • Sesame paste
  • Sesame salt
  • Sesame seed
  • Sesamol
  • Sesamum indicum
  • Sesemolina
  • Sim sim
  • Tahini, Tahina, Tehina
  • Til

Many people with food allergies can generally have highly processed oils, such as well-refined peanut and soybean oil. However, sesame oil isn't as processed and should be avoided by those with sesame allergies.

Here are some foods that may contain sesame:

  • Dishes in Asian cuisine often contain sesame oil.
  • Baked goods (such as bread, breadsticks, hamburger buns, and rolls)
  • Bread crumbs
  • Cereals (like granola and muesli)
  • Chips (such as bagel chips and tortilla chips)
  • Crackers
  • Dipping sauces (such as hummus and tahini sauce)
  • Dressings, gravies, and marinades
  • Falafel can be made with sesame
  • Hummus
  • Herbs and herbal drinks
  • Margarine
  • Processed meats and sausages
  • Protein and energy bars
  • Snack foods (such as pretzels and candy)
  • Sushi
  • Tempeh
  • Turkish cake
  • Vegetarian burgers

It's important to carefully read food labels and inquire about ingredients before consuming any food that you haven't personally prepared.

🔔 Reminder

In packaged foods produced before January 1, 2023, sesame might be present but not declared in ingredients like flavors or spice blends. If uncertain, contact the manufacturer to inquire about their ingredients and production practices.

Reporting Allergic Reactions and Labeling Issues for Food Safety

If you or a family member experiences an allergic reaction to an FDA-regulated food with unclear labeling or a potential allergen, it's essential to act promptly. Here are the steps you should follow:

  1. Seek Professional Guidance: Discuss the allergic reaction with your healthcare provider. They can offer vital insights and recommendations for your specific situation. Additionally, it's advisable to retain the packaging of the food product, as it may contain crucial information.
  2. Contact the Manufacturer: Reach out to the manufacturer of the product in question. They can provide valuable details about ingredients, cross-contamination risks, and production processes. This information is vital for making informed decisions regarding your dietary choices.
  3. Reporting to the FDA: Your voice matters in ensuring food safety for everyone. If you suspect a reaction or encounter labeling concerns, report it to the FDA using one of the following methods:
    1. Contact a Consumer Complaint Coordinator: Consumers and manufacturers can submit detailed reports to an FDA Consumer Complaint Coordinator in the state where the food was purchased.
    2. Call the FDA Hotline: Dial 1-888-SAFEFOOD to report your concerns directly to the FDA.
    3. Utilize FDA's MedWatch Online Form: Visit the FDA's MedWatch Online reporting portal for consumers and submit a detailed report.

When reporting an incident to the FDA, it's crucial to include as much information as possible. This aids in a thorough investigation and ensures appropriate action is taken. Here's what you should include:

  • Identity Details: Provide names, addresses, and contact numbers of both the reporter and the affected individual.
  • Purchase Information: Specify where the product was purchased, including the name and address of the establishment.
  • Reaction Description: Clearly outline the reaction, including the date it occurred, all symptoms experienced, and the timeframe between consumption and reaction onset. Mention any medications used for symptom management.
  • Medical Care Required: Indicate whether the reaction necessitated further medical attention. If so, provide contact information for the attending healthcare professional or facility.
  • Product Information: Offer a comprehensive description of the product, including the purchase date and any codes or marks on the label or container (e.g., lot number, expiration date, UPC code). Additionally, provide visual documentation such as photos of the product, label, ingredient statement, and lot code.

🔔 Reminder

Reporting adverse reactions and labeling concerns is a crucial step in maintaining food safety standards. Your vigilance not only safeguards your well-being but also contributes to the protection of consumers across the board.


Gaining a comprehensive understanding of the major food allergens in the US is vital for the safety and well-being of individuals and families. Advocating for allergen-free options, transparent labeling, and widespread allergy education is crucial.

By promoting a community that prioritizes allergy awareness and safety, we can foster a more inclusive and supportive environment for those managing food allergies.

Always remember to conduct thorough ingredient checks, maintain open communication about allergies, and seek professional guidance when necessary. We can make a positive impact in the lives of those dealing with food allergies, ensuring they can savor their meals with confidence and peace of mind.

FAQs on Food Allergy

Can a food allergy rash occur on the face?

Yes, a food allergy rash on the face can occur. This can include redness, swelling, and itching around the eyes, mouth, or cheeks.

What are some effective food allergy treatments for managing symptoms?

The most effective way to manage a food allergy is to avoid the allergenic food. Additionally, antihistamines may be used to alleviate symptoms, and in severe cases, epinephrine (adrenaline) may be necessary in the form of an auto-injector.

Are there any over-the-counter food allergy medications available?

Yes, there are over-the-counter antihistamine medications, such as cetirizine and loratadine, that can be used to help alleviate mild symptoms of a food allergy.

Can an at-home food allergy test accurately identify specific allergens?

At-home food allergy tests can provide some indication of potential allergens, but it's important to note that they may not be as accurate as tests performed by a healthcare provider in a clinical setting.

What steps should be taken if someone experiences a severe food allergy reaction, including a pronounced skin rash?

In the case of a severe food allergy reaction, which may include a significant food allergy skin rash, it is crucial to administer epinephrine (if prescribed) and seek immediate medical attention by calling 911 or visiting the nearest emergency room.