Food Allergy in Children

If your child develops a rash on the skin, swollen lips, vomiting or difficulty breathing after eating a certain food, one of the possibilities to consider is food allergy.

However, not every tummy ache, wind, diarrhea or skin rash that appears in children after eating a food means food allergy.

Food allergy is the immune system producing an inappropriate immune response to a particular food or to the proteins within that food.

The right diagnosis matters. Because a mistaken diagnosis of food allergy can lead to important foods such as milk, egg, wheat or nuts being removed from the diet unnecessarily, and to the child's nutrition and quality of life being affected.

Are Food Allergy and Food Intolerance the Same Thing?

No.

These two concepts are often confused with each other.

In food allergy the immune system plays a role.

In food intolerance, mechanisms other than the immune system are involved.

For example, in lactose intolerance there is a problem with digesting lactose, the sugar in milk. This can lead to wind, bloating, abdominal pain or diarrhea, but it is not a classic milk protein allergy.

So having discomfort after a food does not automatically mean "allergy to that food".

How Does Food Allergy Develop in Children?

Food allergies can be divided into different groups according to the mechanism of the response the immune system gives.

IgE-Mediated Food Allergy

These reactions mostly appear within minutes of the food being eaten, or within the first few hours.

Symptoms may include;

• Urticaria, that is hives
• Itching
• Swelling of the lips, eyelids or face
• Vomiting
• Cough
• Wheezing
• Shortness of breath
• Anaphylaxis

Non-IgE-Mediated Food Allergy

In these reactions the symptoms generally appear later.

Digestive system symptoms in particular may be prominent.

In some children;

• Repeated vomiting
• Diarrhea
• Blood or mucus in the stool
• Feeding problems
• Abdominal pain
• Growth being affected in certain specific conditions

may be seen.

Mixed-Type Food Allergies

In some conditions both IgE-mediated and other immune mechanisms may play a role together.

For this reason not all food allergies appear in the same way, and they cannot all be diagnosed with the same tests.

Which Foods More Often Cause Allergy in Children?

Theoretically any food can cause an allergic reaction.

The food allergens more commonly encountered in childhood include;

• Cow's milk
• Egg
• Peanut
• Tree nuts
• Wheat
• Soy
• Sesame
• Fish
• Shellfish

Which foods more often cause allergy may change according to the child's age, the geographical region and the eating habits of the community.

How Is Food Allergy Recognized in Babies?

Food allergy in babies can appear in very different ways.

For example, in an IgE-mediated reaction, right after a particular food is taken;

• Urticaria
• Swelling of the lips or around the eyes
• Vomiting
• Cough or wheezing

may be seen.

In some non-IgE-mediated pictures, later-starting symptoms such as;

• Repeated vomiting
• Diarrhea
• Blood in the stool
• Feeding difficulty

may appear.

However, especially during infancy, reflux, colic, constipation, diarrhea and eczema are quite common problems, and none of these on its own means food allergy.

What Is Cow's Milk Allergy?

Cow's milk protein allergy is one of the food allergies encountered particularly during infancy.

It is not the same condition as lactose intolerance.

In cow's milk allergy the immune system reacts to milk proteins, while in lactose intolerance there is a problem with digesting the milk sugar called lactose.

The symptoms of cow's milk allergy may differ according to the mechanism.

In reactions that develop suddenly;

• Urticaria
• Swelling
• Vomiting
• Respiratory symptoms

may be seen.

In some pictures that develop later, digestive system symptoms may be prominent.

Is Egg Allergy Common in Children?

Egg is one of the important food allergens of childhood.

In some children the reaction may appear shortly after egg is eaten, in the form of;

• Urticaria
• Swelling
• Vomiting
• Cough
• Wheezing

However, finding sensitization to egg does not mean that the child will certainly have a clinical reaction to every form of egg.

For example, some children may tolerate well-cooked or baked egg while reacting to less cooked forms.

Assessing this should not be done by trying it at home; it should be done by the doctor according to the child's allergy history.

How Does Food Allergy Show on the Skin?

In food allergy, skin symptoms are especially common in IgE-mediated reactions.

These may be;

• Urticaria
• Itching
• Swelling of the lips and around the eyes
• Flushing of the face

However, not every eczema flare-up is a food allergy.

Especially in children with atopic dermatitis, having a broad food panel done and cutting out a large number of foods simply because eczema is present is not correct.

Does Food Allergy Cause Vomiting?

Yes.

Repeated vomiting occurring within a short time after a particular food is taken may be part of an IgE-mediated reaction in particular.

Vomiting may also be an important symptom in some non-IgE-mediated food allergies.

However, since vomiting in children has many causes including infection, reflux and different gastrointestinal conditions, a diagnosis of food allergy cannot be made by looking at vomiting alone.

Does Food Allergy Cause Bloody Stools?

In some non-IgE-mediated food allergies, blood may be seen in the stool in the form of streaks or spots, especially during infancy.

However, blood in a baby's stool may have causes other than food allergy.

For this reason the baby needs to be evaluated.

Can Food Allergy Cause Anaphylaxis?

Yes.

The most serious reaction of IgE-mediated food allergy is anaphylaxis.

After a food is taken;

• Difficulty breathing
• Wheezing
• Swelling of the tongue or throat
• Change in voice
• Widespread urticaria together with respiratory or circulatory symptoms
• Repeated severe vomiting
• Dizziness
• Fainting
• Change in consciousness

may appear.

Anaphylaxis requires emergency treatment.

In children at risk of anaphylaxis, the family should be taught how to recognize the symptoms, what to do in an emergency and, in suitable patients, how to use an adrenaline auto-injector.

How Is Food Allergy Diagnosed?

The most important step in diagnosing food allergy is a detailed clinical history.

The following questions are particularly important:

Which food was eaten?

How much was eaten?

What form was the food in?

How long afterwards did the symptoms start?

Which symptoms appeared?

Had the same food been eaten before?

Did the same reaction happen again?

Can the child eat that food without any problem at other times?

Does the child have eczema, asthma or another allergic condition?

How Is Food Allergy Testing Done?

When IgE-mediated food allergy is suspected;

• Skin prick test
• Measurement of food-specific IgE in the blood

may be used.

In certain selected situations, component-based tests that evaluate particular allergen proteins may also be helpful.

However, a test result on its own does not make the diagnosis.

What Does a Positive Food Allergy Test Mean?

A positive skin test or specific IgE result in the blood mostly shows sensitization to that food.

Sensitization and true clinical food allergy are not the same thing.

For example, if the child drinks milk regularly and has no reaction at all, a test simply coming back positive does not in every case mean that milk should be removed from the diet.

For this reason, one of the basic principles of the current approach to food allergy is this:

A test result should not be interpreted independently of the child's clinical history.

Is It Right to Have an Allergy Panel Done for All Foods?

Generally no.

Having broad panel tests done against a large number of foods to which the child has never reacted can lead to false positive results.

As a result the child may be kept away unnecessarily from foods such as;

• Milk
• Egg
• Wheat
• Hazelnut
• Peanut

that could in fact be eaten safely.

Tests should be chosen for the foods suspected in the clinical history.

What Is an Oral Food Challenge?

In some children the history and allergy tests may not be enough to confirm the diagnosis.

In that case an oral food challenge may be carried out.

The suspected food is given to the child starting from small amounts, in a controlled way and in increasing doses, and it is followed up to see whether a reaction develops.

The oral food challenge is one of the most important methods in diagnosing food allergy.

However, because it carries a risk of provoking a reaction, it should not be done at home.

It should be carried out in a medical setting where an experienced health team is present and emergency care can be given if a serious reaction develops.

How Is Food Allergy Treated?

Treatment varies according to the type of allergy and the child's clinical condition.

In a confirmed food allergy the main approach is safe management of the food responsible.

This does not only mean "not eating that food".

The family should be told;

• Which food is to be avoided
• How to read labels
• Hidden sources of the food
• The risk of cross-contact
• What to do in case of accidental consumption

In children at risk of anaphylaxis a written emergency action plan should be drawn up and an adrenaline auto-injector prescribed to suitable patients. The current EAACI management guideline also recommends allergen avoidance, dietary counseling, a written treatment plan and, where necessary, the provision of an adrenaline auto-injector as the basic approach in confirmed IgE-mediated food allergy.

Can Removing a Food From the Diet Be Harmful?

It can be.

When foods such as;

• Milk
• Egg
• Wheat
• More than one food group

are removed from the diet for a long time, it can become difficult for the child to get enough protein, energy, vitamins and minerals.

For this reason, especially in children with more than one food allergy, it is important that the diet is planned in a way that supports growth and development.

Does Food Allergy Go Away?

The natural course of the allergy varies according to the food responsible and the mechanism of the allergy.

In some children, tolerance may develop over time in food allergies such as milk and egg that begin during infancy in particular.

Peanut, tree nut and certain other food allergies may be more likely to persist.

However, whether a food allergy has gone is not determined by the child's age alone.

During follow-up the clinical history, the change in test results and, where necessary, a controlled oral food challenge are evaluated together.

Should We Give the Child Small Amounts of the Food at Home?

No.

In a diagnosed food allergy, trying to "get the child used to it" by giving small amounts of the allergen at home can cause serious reactions.

Today, treatments such as oral immunotherapy can be applied in some food allergies.

However, oral immunotherapy is not a method families can carry out on their own at home.

Selecting the suitable patient, determining the treatment doses and managing reactions require medical supervision.

The current EAACI guideline recommends oral immunotherapy for peanut allergy particularly in children and adolescents, and also recommends that it be considered in selected patients with milk and egg allergy.

How Should School and Nursery Be Managed for a Child With Food Allergy?

For a child with food allergy;

• Which food the child is allergic to
• The symptoms of a reaction
• What to do in case of accidental consumption
• If there is one, where the adrenaline auto-injector is kept and how it is used

should be known by teachers, carers and the people responsible for looking after the child.

Especially in children at risk of a serious reaction, it is important to have a written emergency action plan.

As the child grows older, he or she should also be informed about their own allergy in a way appropriate to their age.

When Should You Go to the Emergency Department for Food Allergy?

If, after a food is eaten;

• Shortness of breath
• Wheezing
• Swelling of the tongue or throat
• Hoarseness
• Bluish discoloration
• Fainting
• Change in consciousness
• Rapidly progressing multi-system symptoms

develop, emergency evaluation is needed.

In children who have previously been diagnosed with anaphylaxis and prescribed an adrenaline auto-injector, the family should apply the emergency action plan taught to them by their doctor.