Learn the facts about the 9 most common food allergies, and how to prevent these allergies before they start.
Food allergies happen when someone’s immune system treats the proteins in certain foods like foreign invaders, and triggers an allergic reaction whenever someone eats foods with those proteins.
9 foods are responsible for over 90% of food allergies in the United States.
These are the most common food allergies:
- Cow’s Milk
- Tree Nuts
Today, we’ll cover what you need to know about each of these top 9 food allergies, including how common they are and essential facts about them. We’ll also explain how to prevent these common food allergies before they start.
Cow’s Milk Allergy
Cow’s milk allergy is the most common food allergy in children younger than 5 years old.
How many does it affect?: 2-3% of children younger than 3 years old.
When does it usually develop?: Most commonly, before a child’s first birthday. Half of food allergies in children under the age of one are milk allergies.
Is it usually outgrown?: Yes. Most children do “outgrow” their milk allergy (become tolerant to milk eventually). However, some don’t “outgrow” it until their teenage years, and some children end up with milk allergies that last their entire life.
What else should I know about milk allergies?:
- According to one survey, milk is the food that causes the most food allergic reactions in schools.
- Recent reports indicate that in older children, milk allergy is most often associated with severe allergic reactions.
- Milk allergy is different from lactose intolerance and other milk intolerances. Unlike milk allergies, milk intolerances don’t involve the immune system, and usually only involve stomach and GI symptoms.
Learn more about cow’s milk allergy from Food Allergy Research and Education (FARE):
Egg allergy is one of the top 3 food allergies affecting babies and young children.
When does it usually develop?: In childhood.
Is it usually outgrown?: Many children eventually outgrow their egg allergy, but some children don’t outgrow their egg allergy until their teenage years, and some children end up with lifelong egg allergies.
What else should I know about egg allergies?
- Eggs are very hard to avoid, because so many foods contain “hidden” eggs (including pasta, dressings and condiments, and even ice cream). As a result, egg allergies are one of the allergies with the biggest impact on quality of life.
- Since egg often appears in unexpected places, egg allergy families must read food labels carefully to keep their child(ren) safe.
- In a new consensus report, the American Academy of Allergy, Asthma, and Immunology (AAAAI) and other leading allergy organizations recommend introducing egg to babies who haven’t yet developed an egg allergy, in order to prevent future egg allergies.
Learn more about egg allergy from FARE:
Along with cow’s milk allergy and egg allergy, peanut allergy is one of the top 3 food allergies affecting babies and young children.
How many does it affect?: Up to 2% of all children.
When does it usually develop?: In childhood, most often in early childhood.
Is it usually outgrown?: No — peanut allergies tend to be lifelong. Only 20% of children outgrow their peanut allergy.
What else should I know about peanut allergies?
- In the last 20-25 years, the rate of peanut allergies has tripled in the U.S.
- Peanut allergies are frequently associated with life-threatening anaphylaxis (a severe allergic reaction that affects more than one organ system), more often than most other food allergies.
- Peanut allergies are the only food allergy with an FDA-approved oral immunotherapy treatment available (known as PALFORZIA).
- In a new consensus report, the American Academy of Allergy, Asthma, and Immunology (AAAAI) and other leading allergy organizations recommend introducing peanut to babies who haven’t yet developed a peanut allergy, in order to prevent future peanut allergies.
Learn more about peanut allergy from FARE:
Tree Nut Allergies
The term “tree nut allergies” includes all types of allergies to nuts that grow on trees. The six most common tree nut allergies (in people of all ages) are allergies to walnut, almond, hazelnut, pecan, cashew and pistachio.
How many do they affect?: When they’re counted all together, tree nut allergies affect around 1% of children and adults.
When do they usually develop?: In childhood.
Are they usually outgrown? No. Unfortunately, tree nut allergies are very unlikely to be outgrown. Only about 9% of children eventually outgrow their tree nut allergy, according to FARE.
What else should I know about tree nut allergies?
- Someone with a tree nut allergy could have an allergy to 1, 2, or several types of tree nuts.
- If someone has an allergy to one tree nut, that doesn’t always mean that they must avoid all types of tree nuts. Many people with tree nut allergies only have allergic reactions to 1 or 2 types.
- Certain types of tree nut allergies tend to show up together, because the proteins in those tree nuts are very similar to each other. For example, pecans and walnuts have similar proteins, so these types of tree nut allergies often show up together in the same person. The same goes for cashew and pistachio proteins and allergies.
- If someone has a peanut allergy, they may be more likely to develop a tree nut allergy. 30% of people with peanut allergies are also allergic to tree nuts.
- Tree nut allergies are one of the food allergy types most likely to cause severe reactions (along with peanut and milk allergies).
A wheat allergy is completely different from gluten intolerances. A wheat allergy causes allergic reactions when the immune system detects a protein that’s only found in wheat. But gluten intolerances are immune responses to gluten, a protein that can be found in many different grains.
How many does it affect?: Around 0.4% of children.
When does it usually develop?: In childhood.
Is it usually outgrown?: Yes. Wheat allergies are often outgrown in childhood. But some wheat allergies still last into adulthood.
What else should I know about wheat allergies?
- Wheat sometimes appears in unexpected places, like hot dogs, sauces, ice cream, hot dogs, and fried breaded foods. So, wheat allergy families need to read food labels carefully to keep their child(ren) safe.
- People with wheat allergies can develop allergic reactions to cosmetic products with wheat in them, if these products touch their lips.
- But wheat doesn’t have to be clearly listed on cosmetic product labels, so wheat allergy families have to read cosmetics labels very carefully.
Soy allergies usually affect infants and young children under 3 years old.
When does it usually develop?: In early childhood (before age 3).
Is it usually outgrown?: Most children with soy allergies eventually outgrow the allergy. According to one study, around 25% of children outgrow their soy allergy by age 4, around 45% outgrow their soy allergy by age 6, and almost 70% outgrow it by age 10. But some soy allergies persist into adulthood.
What else should I know about soy allergies?
- Since so many foods contain hidden soy, soy allergies can be especially challenging Soy allergy families must read food labels carefully. For the full breakdown of how soy sometimes “hides” in foods, please read this article from FARE.
- Even though soybeans and peanuts are both in the legume family, the two allergies aren’t related. Having a peanut allergy doesn’t make someone more likely to develop a soy allergy, and vice versa.
“Fish allergies” refers to finned fish allergies, a different category from shellfish allergies. When someone has a finned fish allergy, they are allergic to one or more specific types of finned fish.
Some common types of fish allergies include salmon allergy, cod allergy, tuna allergy, and tilapia allergy.
How many do they affect?: Around 0.5%-0.6% of children.
When do they usually develop?: In adulthood. Finned fish allergies are more common in adults than children, and more common in children ages 6-17 than young children ages 0-5.
Also, around 40% of people with a fish allergy have their first allergic reaction to fish as adults.
Are they usually outgrown?: No. Finned fish allergies tend to be lifelong.
What else should I know about fish allergies?
- There are over 20,000 types of fish in the world, and a finned fish allergy could develop to any type.
- Even being exposed to steam from cooking finned fish could trigger a fish allergy reaction.
- More than half of people with a fish allergy are allergic to two or more types of fish.
Shellfish allergies include allergies to crustaceans (like crab, lobster, shrimp, and crayfish) and to mollusks (like scallops, oysters, mussels clams, and squid). They are different from finned fish allergies.
How many do they affect?: Around 1-1.5% of children.
When do they usually develop?: In adulthood. 60% of people with allergies to any shellfish have their first allergic reaction as adults.
Are they usually outgrown?: No. Shellfish allergies tend to be lifelong.
What else should I know about shellfish allergies?
- Severe shrimp allergy reactions are much rarer in children than in adults, as an AAAAI study has shown.
- Crustacean allergies are more common than, and tend to cause more severe reactions than, mollusk allergies.
- Many shellfish allergies involve a protein called tropomyosin. According to one report, over 60 % of people with shellfish allergies react to tropomyosin.
Sesame allergy is the ninth-most common food allergy in the United States. It has only been recognized as a top allergen under food labeling laws as of 2021.
How many does it affect?: Over 1.5 million children and adults in the United States (between 0.2% and 0.5% of the general population).
When does it usually develop?: In childhood, but it could develop anytime.
Is it usually outgrown?: No. Only around 20-30% of children with sesame allergies eventually outgrow their allergy.
What else should I know about sesame allergy?
- Now that the FASTER Act has been passed, manufacturers will need to clearly label food products that contain sesame, just like they must label products that contain the other eight top allergens. But this isn’t required until January 2023.
- In the meantime, sesame isn’t currently listed clearly on all ingredient labels in the U.S. This makes it very difficult to identify the foods that contain sesame, and that could cause a sesame allergic reaction.
- Sesame appears in many unexpected places and under many “hidden” names. In fact, sesame may also appear in spice blends and flavorings without being listed as an ingredient, until the 2023 labeling law fully takes effect.
- Around 80% of people with sesame allergies have at least one other food allergy. So, someone who already has another food allergy is more likely to develop sesame allergies.
Preventing Food Allergies Before They Start
Thanks to landmark clinical trials and several sets of recent medical guidelines, we now know that introducing foods responsible for the most common food allergies to babies is a way to help prevent food allergies before they start.
For example, in their 2020-2025 Dietary Guidelines, the USDA (U.S. Department of Agriculture) recommends that “potentially allergenic foods (e.g., peanuts, egg, cow’s milk products, tree nuts, wheat, crustacean shellfish, fish, and soy) should be introduced when other complementary foods are introduced to an infant’s diet.” After all, says the USDA, “There is no evidence that delaying introduction of allergenic foods, beyond when other complementary foods are introduced, helps to prevent food allergy.”
As we mentioned above, the AAAAI’s recent recommendation is even stronger. “To prevent peanut and/or egg allergy,” says the AAAAI, “both peanut and egg should be introduced around 6 months of life, but not before 4 months.”
All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.
These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.