Common food allergies include dairy, peanuts, and tree nuts, among others. You may be more likely to outgrow certain allergies than others.
Food allergies are extremely common. In fact, they affect around 6% of adults and 8% of children — and these percentages are rising (1, 2).
One study suggests that nearly 11% of adults in the United States have a food allergy (3).
Although it’s possible for any food to cause an allergy, most food allergies are caused by just eight foods (4). According to the Food and Drug Administration (FDA), these 8 foods cause 90% of food allergic reactions in the United States (5).
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
What is a food allergy?
A food allergy is a condition in which certain foods trigger an abnormal immune response (6).
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.
Food allergy symptoms
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
- vomiting
- diarrhea
- hives
- 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 (7).
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.
Types of food allergies
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 (8).
- 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 (8).
Here are the eight most common food allergies.
1. Cow’s milk
An allergy to cow’s milk is most often seen in babies and young children (9).
It’s one of the most common childhood allergies, affecting 2–3% of babies and toddlers (10).
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 (11).
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 (12).
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
- milk powder
- cheese
- butter
- margarine
- yogurt
- cream
- 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 (13).
SUMMARY
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.
2. Eggs
An egg allergy is the second most common cause of food allergy in children (14).
However, 68% of children who are allergic to eggs will outgrow their allergy by the time they’re 16 years old(14).
Symptoms include:
- 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 (15).
Like other allergies, the treatment for an egg allergy is an egg-free diet (15).
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 (16, 17).
In fact, one study found that nearly 67% of children with an egg allergy could tolerate eating muffins containing a cooked egg component (16).
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 (18).
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.
SUMMARY
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.
It’s a very common food allergy that’s thought to affect around 1% of the U.S. population and perhaps up to 3% of people worldwide (19, 20, 21).
Some examples of tree nuts include:
- Brazil nuts
- almonds
- cashews
- macadamia nuts
- pistachios
- pine nuts
- walnuts
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 (22).
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.
Allergies can also be very severe, and tree nut allergies are responsible for around 50% of anaphylaxis-related deaths (23, 24).
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 (25).
SUMMARY
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.
4. Peanuts
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, studies have since shown that introducing peanuts early may be protective (26, 27).
Peanut allergies affect around 1–3% of children and up to 2% of adults (26, 28).
However, around 15–22% of children who develop a peanut allergy will find it resolves as they move into their teenage years (8).
Like other allergies, a peanut allergy is diagnosed using a combination of:
- health history
- skin-prick testing
- blood tests
- food challenges
At the moment, the only effective treatment is avoidance of all peanuts and peanut-containing products (26, 29).
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 (30, 31).
SUMMARY
A peanut allergy is a serious condition that can cause a severe allergic reaction. Treatment is lifelong avoidance of peanuts and peanut-containing products.
5. Shellfish
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:
- shrimp
- prawns
- crayfish
- lobster
- squid
- scallops
The most common trigger of a seafood allergy is a protein called tropomyosin. Other proteins that may play a role in triggering an immune response are arginine kinase and parvalbumin (32, 33).
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 (34).
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 (35).
SUMMARY
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.
6. Wheat
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 (36).
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 (37).
Celiac disease and non-celiac gluten sensitivity are caused by an abnormal immune reaction to one specific protein — gluten — that also happens to be found in wheat (38, 39).
Celiac disease can also be fatal in 10 to 30% of people, though this is rare as most are able to successfully avoid gluten (40).
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.
SUMMARY
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.
7. Soy
Soy allergies affect up to 0.5% of children and are most commonly seen in infants and children under 3 years old (41).
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 (43).
A small number of babies who are allergic to cow’s milk are also allergic to soy (43).
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.
SUMMARY
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.
8. Fish
Fish allergies are common, affecting up to around 7% of adults (44).
Similar to other allergies, people often develop fish allergies during childhood (45). But it’s not uncommon for a fish allergy to surface later in life (46).
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.
Because the symptoms can be similar, a fish allergy is sometimes confused for a reaction to a contaminant in fish, such as bacteria, viruses, or toxins (47, 48, 49).
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.
SUMMARY
Fish allergies are common, but they may be confused with an adverse reaction to contaminated fish.
Other foods
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:
- linseed
- sesame seed
- peach
- banana
- avocado
- kiwi fruit
- passion fruit
- celery
- garlic
- mustard seeds
- aniseed
- chamomile
SUMMARY
Any food can cause an allergy. Other foods people may be allergic to include fruits, vegetables, and seeds like linseed or sesame seed.