Any food can cause an allergy. However, just a handful of foods cause at least 90 percent of allergic reactions to food. The substance that causes an allergic reaction in foods or drinks is called an “allergen.”
As far as foods are concerned, nearly all allergens are proteins. For the majority of people, these proteins are not allergens, because their immune system does not react to them. It is the immune system’s reaction to these proteins that causes an allergic reaction.
Among children, most allergic reactions to food are caused by peanuts, milk, soybean, tree nuts, eggs, and wheat. The majority of children stop being allergic to foods early on in their childhood. Allergic adults typically react to citrus fruit, nuts, fish, peanuts, shellfish, and wheat.
Like most food allergies, egg allergy is more common in childhood and about half of children who have it will grow out of it by the age of 3. In a few cases, egg allergy can cause anaphylaxis.
Three proteins cause egg allergy:
Cooking can destroy some of these allergens, but not others. So, some people might react to cooked eggs, as well as raw eggs.
Occasionally, someone might react to egg because they have an allergy to chicken, quail, or turkey meat, or to bird feathers. This is called bird-egg syndrome.
Fish allergy can often cause severe reactions, including anaphylaxis. Adults are more likely to have an allergic reaction to fish and shellfish than children, which is probably because adults eat these foods more often.
People who are allergic to one type of fish, such as cod, often react to other types of fish, such as hake, haddock, mackerel, and whiting.
This is because the allergens in these fish are quite similar. Cooking doesn’t destroy fish allergens. In fact, some people with a fish allergy can be allergic to cooked but not raw fish.
Allergy to cows’ milk is the most common food allergy in childhood. A reaction can be triggered by small amounts of milk, either passed to the baby through the mother’s breast milk from dairy products she has eaten, or from feeding cows’ milk to the baby.
Children usually grow out of milk allergy by but about one-fifth of children who have an allergy to cows’ milk will still be allergic to it as adults.
Milk allergy symptoms
The symptoms of milk allergy are often mild and can affect any part of the body. They can include:
In very few cases, milk allergy can cause anaphylaxis.
Nuts from trees
Allergy to nuts from trees is usually lifelong. The nuts that are most likely to cause allergic reactions are: