One study suggests that nearly 11% of adults in the United States have a food allergy (
Although it’s possible for any food to cause an allergy, most food allergies are caused by just eight foods (
This article is a detailed review of the 8 most common food allergies. It discusses:
- their symptoms
- who is at risk
- what you can do about it
A food allergy is a condition in which certain foods trigger an abnormal immune response (
It’s caused by your immune system wrongly recognizing some of the proteins in a food as harmful. Your body then launches a range of protective measures, including releasing chemicals like histamine, which causes inflammation.
For people who have a food allergy, even exposure to very small amounts of the problem food can cause an allergic reaction.
Symptoms can occur anywhere from a few minutes after exposure to a few hours or even a few days later, depending on the type of allergy. They may include some of the following:
- swelling of the tongue, mouth, or face
- difficulty breathing
- low blood pressure
- itchy rash
In more severe cases, a food allergy can cause anaphylaxis. Symptoms, which can come on very quickly, include an itchy rash, swelling of the throat or tongue, shortness of breath, and low blood pressure. Some cases can be fatal (
Many food intolerances are often mistaken for food allergies.
However, food intolerances never involve the immune system. This means that while they can severely affect your quality of life, they are not life threatening.
True food allergies can be divided into two main types:
- Immunoglobulin E (IgE) mediated. In this type of food allergy, your body’s immune system makes IgE antibodies that react with certain food. Antibodies are a type of blood protein used by your immune system to recognize and fight infection. An IgE-mediated allergic reaction usually occurs within several hours of eating the food allergen and can include mild to severe symptoms, including anaphylaxis (
- Non-IgE mediated. In a non-IgE food allergy, your immune system does not make IgE antibodies, but other parts of the immune system are engaged in mounting a response against the perceived threat. A non-IgE mediated allergic reaction often involves skin or digestive symptoms, or a combination of those symptoms, including vomiting and diarrhea, and can occur up to 3 days after eating the food allergen (
Here are the eight most common food allergies.
1. Cow’s milk
It’s one of the most common childhood allergies, affecting 2–3% of babies and toddlers (
However, around 90% of children will outgrow the condition by the time they’re 3 years old, making it much less common in adults.
A cow’s milk allergy can occur in both IgE and non-IgE forms, but IgE cow milk allergies are the most common and potentially the most serious.
Children or adults with an IgE allergy tend to have a reaction within 5–30 minutes of ingesting cow’s milk. They experience symptoms like swelling, rashes, hives, vomiting, and, in rare cases, anaphylaxis.
A non-IgE allergy usually has more gut-based symptoms like vomiting, constipation, or diarrhea, as well as inflammation of the gut wall (
A non-IgE milk allergy can be quite difficult to diagnose. This is because sometimes the symptoms can suggest an intolerance and there is no blood test for it (
If a diagnosis of a cow’s milk allergy is made, the only treatment is to avoid cow’s milk and foods that contain it. This includes any foods or drinks that contain:
- milk powder
- ice cream
Breastfeeding mothers of babies with an allergy may also have to remove cow’s milk and foods that contain it from their own diets.
As for babies who are not breastfeeding, a healthcare professional will recommend a suitable alternative to a cow’s milk–based formula (
A cow’s milk allergy mostly affects children under 3 years old. A cow’s milk allergy diagnosis means that all milk and milk products must be avoided.
However, 68% of children who are allergic to eggs will outgrow their allergy by the time they’re 16 years old(
- digestive distress, such as a stomach ache
- skin reactions, such as hives or a rash
- respiratory problems
- anaphylaxis (which is rare)
It’s possible to be allergic to egg whites but not the yolks, and vice versa. This is because the proteins in egg whites and egg yolks differ slightly.
Yet, most of the proteins that trigger an allergy are found in egg whites, so an egg white allergy is more common (
Like other allergies, the treatment for an egg allergy is an egg-free diet (
However, you may not have to avoid all egg-related foods, as heating eggs can change the shape of the allergy-causing proteins. This can stop your body from seeing them as harmful, meaning they’re less likely to cause a reaction (
In fact, one study found that nearly 67% of children with an egg allergy could tolerate eating muffins containing a cooked egg component (
Some studies have also shown that introducing baked goods to children with an egg allergy can shorten the time it takes for them to outgrow the condition; however, results are conflicting, and more data is needed to confirm this (
The consequences of ingesting eggs when you are allergic to them can be severe. Because of this, you should check with your doctor before you reintroduce any egg-containing foods.
The most common type of egg allergy is an egg white allergy. The treatment is an egg-free diet. However, some people may be able to reintroduce some foods containing cooked eggs into their diet.
3. Tree nuts
A tree nut allergy is an allergy to some of the nuts and seeds that come from trees.
Some examples of tree nuts include:
- Brazil nuts
- macadamia nuts
- pine nuts
People with a tree nut allergy will also be allergic to food products made with these nuts, such as nut butters and oils.
They are advised to avoid all types of tree nuts, even if they’re only allergic to one or two types (
This is because being allergic to one type of tree nut increases your risk of developing an allergy to other types of tree nuts.
Additionally, it’s easier to avoid all nuts, rather than just one or two types. And unlike some other allergies, an allergy to tree nuts is usually a lifelong condition.
Because of this, people with nut allergies (as well other potentially life threatening allergies) are advised to carry an epinephrine auto-injector, like EpiPen, with them at all times.
An epinephrine auto-injector is a potentially life-saving device that allows those with allergies to inject themselves with a shot of adrenaline if they begin to have a severe allergic reaction. Adrenaline, also known as epinephrine, is a naturally occurring hormone that stimulates your body’s “fight or flight” response when you’re stressed.
When given as an injection to people having a severe allergic reaction, it can reverse the effects of the allergy and save the person’s life (
A tree nut allergy is one of the most common food allergies. It’s frequently associated with severe allergic reactions, and the treatment is usually a lifelong avoidance of all tree nuts and tree nut products.
Like a tree nut allergy, peanut allergies are very common and can cause severe and potentially fatal allergic reactions.
However, the two conditions are considered distinct, as a peanut is a legume. Nevertheless, those with peanut allergies are often also allergic to tree nuts.
While the reason people develop a peanut allergy isn’t known, it is thought that people with a family history of peanut allergies are most at risk.
Because of this, it was previously thought that introducing peanuts through a breastfeeding mother’s diet or during weaning may trigger a peanut allergy.
However, around 15–22% of children who develop a peanut allergy will find it resolves as they move into their teenage years (
Like other allergies, a peanut allergy is diagnosed using a combination of:
- health history
- skin-prick testing
- blood tests
- food challenges
However, new treatments are being developed for children with peanut allergies. These involve giving precise and small amounts of peanuts or peanut allergen powder under strict medical supervision in an attempt to desensitize them to the allergy (
A peanut allergy is a serious condition that can cause a severe allergic reaction. Treatment is lifelong avoidance of peanuts and peanut-containing products.
A shellfish allergy is caused by your body attacking proteins from the crustacean and mollusk families of fish, which are known as shellfish.
Examples of shellfish include:
Symptoms of a shellfish allergy usually come on quickly and are similar to other IgE food allergies.
However, a true seafood allergy can sometimes be hard to distinguish from an adverse reaction to a contaminant of seafood, such as bacteria, viruses, or parasites.
This is because the symptoms can be similar, as both can cause digestive issues like vomiting, diarrhea, and stomach pain.
A shellfish allergy doesn’t tend to resolve over time, so most people with the condition must exclude all shellfish from their diet to avoid having an allergic reaction (
Interestingly, even the vapors from cooking shellfish can trigger a shellfish allergy in those who are allergic. This means that many people are also advised to avoid being around seafood when it’s being cooked (
The most common trigger of a shellfish allergy is a protein called tropomyosin. The only treatment for a shellfish allergy is removing all shellfish from your diet.
A wheat allergy is an allergic response to one of the proteins found in wheat.
It tends to affect children the most. Although, children with a wheat allergy often outgrow it by the time they reach 10 years old (
Like other allergies, a wheat allergy can result in digestive distress, hives, vomiting, rashes, swelling, and in severe cases, anaphylaxis.
It’s often confused with celiac disease and non-celiac gluten sensitivity, which can have similar digestive symptoms.
However, a true wheat allergy causes an immune response to one of the hundreds of proteins found in wheat. This reaction can be severe and sometimes even fatal (
People with celiac disease or non-celiac gluten sensitivity have to avoid wheat and other grains that contain the protein gluten.
Those with a wheat allergy only need to avoid wheat and can tolerate gluten from grains that do not contain wheat.
A wheat allergy is often diagnosed through skin-prick testing.
The only treatment is to avoid wheat and wheat-containing products. This means avoiding foods, as well as beauty and cosmetic products, that contain wheat.
A wheat allergy can be caused by a sensitivity to any of the hundreds of proteins in wheat. The only treatment is a wheat-free diet, but many people outgrow it before they reach school age.
They’re triggered by a protein in soybeans or soybean-containing products. However, around 70% of children who are allergic to soy outgrow the allergy (42).
The symptoms can range from an itchy, tingly mouth and runny nose to a rash and asthma or breathing difficulties. In rare cases, a soy allergy can also cause anaphylaxis (
A small number of babies who are allergic to cow’s milk are also allergic to soy (
Common food triggers of soy allergy include soybeans and soy products like soy milk or soy sauce. Since soy is found in many foods, it’s important to read food labels.
Like other allergies, the only treatment for soy allergy is the avoidance of soy.
A soy allergy is triggered by the proteins in soybeans and soybean products. If you have a soy allergy, the only treatment is the removal of soy from your diet.
Like a shellfish allergy, a fish allergy can cause a serious and potentially fatal allergic reaction. The main symptoms are vomiting and diarrhea, but, in rare cases, anaphylaxis can also occur.
This means that those who are allergic to fish are usually given an epinephrine auto-injector to carry in case they accidentally eat fish.
What’s more, since shellfish and fish with fins don’t carry the same proteins, people who are allergic to shellfish may not be allergic to fish.
However, many people with a fish allergy are allergic to one or more types of fish.
Fish allergies are common, but they may be confused with an adverse reaction to contaminated fish.
The 8 food allergies outlined above are the most common ones.
However, there are many more.
Less common food allergies can cause an array of symptoms, ranging from mild itching of the lips and mouth (known as oral allergy syndrome) to life threatening anaphylaxis.
Some less common food allergies include:
- sesame seed
- kiwi fruit
- passion fruit
- mustard seeds
Any food can cause an allergy. Other foods people may be allergic to include fruits, vegetables, and seeds like linseed or sesame seed.
Sometimes it can be difficult to tell the difference between food allergies and food intolerances.
If you suspect you have a food allergy, it’s important to speak with a doctor.
- Dietary review. This is a detailed review of foods eaten, including timing and symptoms.
- Skin prick testing. For this test, a small amount of food is “pricked” into the skin using a tiny needle. The skin is then monitored for a reaction.
- Oral food challenges. For this test, the problem food is eaten in a controlled environment under medical supervision in gradually increasing amounts.
- Blood tests. In some circumstances, blood will be drawn, and the level of IgE antibodies is measured.
If you’re allergic to a food, your doctor will advise you on how to manage it. Your doctor may also refer you to a registered dietitian to help with managing your diet.
If you suspect you have a food allergy, speak with a doctor. They can diagnose the condition through a number of tests.
Currently, food allergies cannot be cured (
Whether you have an IgE-mediated or non-IgE–mediated food allergy, the best way to avoid an allergic reaction is to identify the foods you are allergic to and strictly avoid them.
Depending on the severity of your food allergy, your healthcare professional may prescribe medications, including epinephrine auto-injectors, for you to carry with you at all times in case you accidentally ingest and have a reaction to a food you’re allergic to (
- Epinephrine. This medication helps reverse symptoms of a serious type of allergic reaction called anaphylaxis. Brand-name epinephrine auto-injectors include EpiPen and Auvi-Q.
- Antihistamines. These medications can help reduce itching and congestion from less severe allergic reactions.
- Corticosteroids. These medications may be prescribed to reduce swelling from more severe allergic reactions.
It is important to take all symptoms of food allergy seriously. Both mild and severe symptoms of an IgE-mediated allergic reaction can lead to anaphylaxis, which is a medical emergency.
While non-IgE–mediated food allergies are less likely to lead to anaphylaxis, they can significantly affect quality of life and should be addressed.
If you suspect you have a food allergy, consult a doctor or allergist to determine which foods you’re allergic to and should avoid.
You may also find it helpful to meet with a registered dietitian who can help you safely avoid foods you’re allergic to while ensuring you’re eating a varied, balanced diet that meets your nutrient needs.
Most food allergies are caused by eight foods: cow’s milk, eggs, tree nuts, peanuts, shellfish, fish, soy, and wheat.
Unlike food intolerances, food allergies are caused by your immune system incorrectly identifying some of the proteins in food as harmful.
This can cause potentially life threatening reactions. The only treatment is the removal of the food from your diet.
If you suspect you have a food allergy, speak with a doctor about it.