Food allergy: what are the most common foods?

When the child begins to receive foods other than breast milk, in general, insecurity arises regarding possible food allergies. According to data from the Brazilian Society of Pediatrics, between 6% and 8% of children and adolescents are allergic to any food.

But anyone who thinks that adults are free of this is mistaken. Although many conditions have eased over the years, approximately 1% of adults are still sensitive to some foods.

Incidentally, sometimes, the allergy can arise after years of consuming the food.


What is a food allergy?

Food allergy is an exaggerated response by the body to certain food proteins . When the person ingests the food, the immune system, previously sensitive to them, triggers reactions, as if those components were aggressive or dangerous to the body.

Although there is a group of foods more related to allergies, it is possible to be sensitive to anything. In addition, the symptoms are also quite variable, depending on the sensitivity of each organism.

Some children with allergies may experience spontaneous improvement until the end of childhood or adolescence. But many will continue with some degree of sensitivity throughout their lives.

And even those who grew up free from the exaggerated responses of the body can, at any time, manifest symptoms of allergy after eating something.

In general, skin reactions (such as rashes, itching, redness), gastric reactions (nausea, vomiting), intestinal reactions ( diarrhea ) are some of the most common.

What are the symptoms of food allergy?

Allergies occur more or less like this: the immune system is responsible for the defense of the body. It fights infectious agents or foreign bodies that end up penetrating the mouth or nose.

In other words, the mechanism of food allergy is the same as that of rhinitis, for example.

In the case of people with allergies, there is a small misidentification. It is not clear why, but for allergic people, immunity responds excessively to food proteins that are harmless to most other people.

After ingestion – that is, a snack or lunch – the defense process begins. Then the leukocytes, which are immune cells present in the blood, are activated and end up overreacting to the substance.

A specific type of antibody, the immunoglobulin IgE, begins to act and causes the release of histamine, a substance that generates symptoms.

The intensity and duration of the symptoms will depend on the person’s sensitivity, as well as the amount of food eaten. Among the most common are:


When the allergen enters the body, one of the organs that most manifests reactions is the skin.

There is a release of histamine, which, on the skin, causes manifestations such as edema, rashes, redness and itching.


Respiratory manifestations can also occur due to the action of histamine. Thus, allergic rhinitis, bronchospasm, asthma , difficulties in breathing and itchy throat are common.

Rapid, intense and localized swelling can occur, which normally affects the eyelids, lips, but also the tongue and throat.

Angioedema, which is this swelling, can cause breathing difficulties and even lock your throat, leading to death.


Acute intestinal spasm, eosinophilic esophagitis , nausea, vomiting, colic and intestinal contractions may occur. In general, they are symptoms related to late manifestations – that is, they appear after a few hours that the food has been ingested.

What foods are most often involved in food allergy?

Every food has the potential to be an allergy-triggering agent. But there are some more common ones. Cow’s milk, eggs, soybeans, wheat, crustaceans, peanuts are on the list of the most allergenic, being responsible for about 90% of allergic conditions and cases.

Cow milk

Food is considered to be one of the main food allergens in the world. And people allergic to cow’s milk, in general, tend to be sensitive to other mammals as well, such as goats, buffalo and sheep.


People sensitive to hen’s egg white proteins are estimated to react poorly to eggs from other birds as well. However, anyone who is allergic to egg yolk may be sensitive to chicken meat, according to the Brazilian Consensus on Food Allergy.


Anyone who is allergic to shrimp, in general, is at risk of being allergic to other crustaceans, such as crabs, lobster and crab. When a reaction occurs, the tendency is for the symptoms to take longer than reactions to milk or eggs.

Chestnuts and peanuts

Anyone who has had an allergic reaction to a type of chestnut or peanut has a good chance of manifesting symptoms to other oilseeds as well. Like crustaceans, symptoms tend to take longer to disappear than those caused by milk or eggs.

Why are some people allergic to shrimp?

Like any other allergy, the one caused by shrimp still does not have a very clear mechanism. In general, it is known that the person has a genetic predisposition. When exposed to food, the body overreacts and triggers symptoms.

Many people take too long to taste the shrimp, eating only in adulthood. This causes the body to delay being exposed to the allergen and, thus, the reaction occurs only in adulthood.

But it is worth remembering that it is possible to grow up eating the seafood and, even so, have a reaction already in adulthood.

Sometimes the condition is aggravated because the person is very sensitive, with cases in which only the steam from cooking can lead to reactions. Without knowing that you are allergic, you end up eating a large amount and, thus, the symptoms are quite intense.

What to do in case of severe allergy?

Being an emergency, that is, at the time of the allergic reaction, the most important thing is to seek medical attention. So, you have to go to the hospital.

It is worth remembering that, in some cases, allergies can manifest immediate and late symptoms. In other words, even if everything seems controlled, the situation can get worse. In general, drugs are used to control symptoms and stabilize the condition.

Histamine blockers, mast cell stabilizers and even corticosteroids can be prescribed. However, after that, it is necessary for the person to identify allergens and adopt precautionary measures, avoiding contact or ingestion.


Do you want to know more about allergies and food care? Follow the Healthy Minute!