Food Allergy in Children

What is Food Allergy in Children?

Food allergy in children and infants refers to hypersensitivity reactions in the body against certain foods mediated by the immune system. A food allergy occurs when the immune system overreacts to specific foods.

The body treats these foods as harmful substances and releases chemicals like histamine. This can lead to symptoms such as itching, rash, stomach pain, vomiting, and diarrhea. In more severe cases, life-threatening conditions like shortness of breath and anaphylaxis may develop. Food allergies are commonly seen against foods such as milk, eggs, peanuts, seafood, and wheat.

What Causes Food Allergy in Children?

Food allergy in infants and children arises due to genetic changes inherited from the mother and/or father in the immune cells, which are the building blocks of the immune system, and in the communication system between these cells.

Genetic changes affecting the skin, which acts as a barrier protecting our body from external factors, also play a role in the development of cow’s milk allergy in children. Environmental factors contribute to this condition as well. Babies with eczema at around 3-4 months of age are at higher risk for food allergies.

Recent studies have also shown that foods consumed by mothers during pregnancy and by babies in the first two years after birth can negatively affect the bacteria that form the normal gut flora and the immune components surrounding the intestines, potentially leading to food allergies during childhood.

The Role of the Immune System in Food Allergy in Children

Food allergy occurs due to an abnormal response of the immune system cells of the baby or child against food proteins. Genetic traits inherited from the mother and/or father, together with environmental factors, play a role in this abnormal response by affecting immune cells and the communication between these cells.

Furthermore, recent studies indicate that consuming processed packaged foods, foods high in excessive sugar but poor in natural fiber and antioxidants, and foods with additives during pregnancy and the first two years of the baby's life can negatively impact the bacteria that constitute the normal gut flora and the immune elements surrounding the intestines, thus contributing to food allergies in childhood.

Consumption of fiber-rich whole grains, vegetables and fruits, raw nuts, olive oil, and foods rich in antioxidants, while avoiding processed foods, strengthens the immune system.

What are the Symptoms of Food Allergy in Children?

Symptoms of Food Allergy Are Grouped into Three Main Types:

1. Immediate-Type (IgE-Mediated) Food Allergy

After consuming the suspected food, symptoms appear suddenly within minutes or up to two hours. These include redness, swelling, and widespread itching on the skin; severe abdominal pain; vomiting; coughing; sneezing; runny nose; nasal congestion; shortness of breath; wheezing from the chest; difficulty swallowing; hoarseness or change in voice; palpitations; feeling faint; and in very severe cases, loss of consciousness and fainting. One or several of these symptoms may occur together. Skin involvement is the most common symptom. If other vital organs or systems are affected, this condition is called anaphylaxis.

2. Mixed-Type Food Allergy

In mixed-type allergy, symptoms related to food allergy develop hours or days after consumption of the triggering food. The most common symptom is moderate to severe atopic dermatitis (eczema). Eczema rashes can appear in babies either from direct consumption of the allergen or when exclusively breastfed infants are exposed to allergens through the mother’s diet.

Another clinical condition is eosinophilic esophagitis, an inflammation of the esophagus, which can also be caused by food allergy. It can occur at any age, including infants, and causes long-lasting loss of appetite, abdominal pain, nausea, intermittent vomiting, sour taste in the mouth, holding food in the mouth, and in severe cases, difficulty swallowing and vomiting.

3. Delayed-Type (Non-IgE-Mediated) Food Allergy

The most common delayed-type reaction in breastfed infants with food allergy is allergic proctocolitis. Proctocolitis is inflammation of the lower part of the large intestine caused by food allergy. Symptoms include bloody and mucous stools, usually seen in infants younger than six months who are exclusively breastfed. The infant’s general condition is usually good, but this condition worries parents.

If symptoms improve after the allergenic food is removed from the mother’s diet, this is an important clue. Definitive diagnosis is made by a food challenge test. If symptoms reoccur when the allergenic food is reintroduced into the mother’s diet, the diagnosis is confirmed.

Food protein-induced enterocolitis syndrome (FPIES) is another delayed-type food allergy. In this condition, vomiting occurs within hours after consuming the allergenic food. Vomiting can be very frequent and last for hours, causing dehydration. In some patients, diarrhea accompanies vomiting.

What Are the Most Common Food Allergens in Babies and Children?

The most common food allergens in infancy are cow’s milk and eggs. In the general childhood age group, common allergens include cow’s milk, eggs, nuts such as hazelnuts, walnuts, pistachios, cashews, peanuts, legumes like lentils, chickpeas, peas, wheat, red meat, sesame, various fish species, and soy.

Besides these, other legumes, crustaceans and mollusks (other than fish),seeds like poppy, sunflower, pumpkin seeds, and various fruits and vegetables may cause allergies in sensitive individuals.

What Are the Differences Between Food Allergy and Food Intolerance?

Food intolerance is a reaction of the digestive system to a consumed food, usually due to the absence or malfunction of an enzyme needed to digest a specific substance in that food.

As a result, the substance cannot be digested properly and causes harm to the body. For example, hereditary fructose intolerance is a genetic disorder where foods containing fructose (fruits) cannot be digested, causing abdominal pain, nausea, vomiting, diarrhea, abdominal swelling, weakness, pallor, hypoglycemia (low blood sugar),growth retardation, jaundice, and liver damage.

In contrast, food allergy in babies and children is an excessive immune response to certain foods mediated by the immune system cells. The body treats these foods as harmful substances and releases chemicals like histamine, leading to symptoms such as itching, rash, abdominal pain, vomiting, and diarrhea. More severe cases can cause life-threatening conditions like shortness of breath and anaphylaxis, or symptoms such as eczema and bloody stools in infants due to food allergy.

How Is Food Allergy Diagnosed in Children and Infants?

To diagnose food allergy in children, a specialist physician first takes a detailed history from the parents regarding the symptoms. Important information includes when the symptoms began, which type of food triggered them, the severity and spread of any immediate-type reactions, how they were treated, and the frequency and pattern of delayed-type symptoms. After evaluating and examining the baby, skin tests and blood tests are performed if needed. Based on these results, a food challenge test may be conducted to confirm the diagnosis of food allergy.

Treatment and Management of Food Allergy in Children

Once a child is diagnosed with food allergy, the foods that the child can safely consume are identified. If the patient is a baby who has started complementary feeding after six months, the allergenic food is removed from the diet, and growth is monitored with a nutrition plan rich in age-appropriate vitamins and minerals. For babies with cow’s milk allergy or other food allergies, breastfeeding is continued. However, if the baby shows symptoms due to allergenic proteins in the mother’s diet, the mother must eliminate the responsible food from her own diet.

Mothers are given a balanced nutrition plan rich in calcium, healthy carbohydrates, fats, and proteins. If the allergen is cow’s milk, the mother is also supplemented with calcium and vitamin D. Consultation with a dietitian may be recommended.

Allergenic foods can be present in many different forms. For example, foods containing cow’s milk include infant formulas, yogurt, cheese, milk-based cakes, cookies, pancakes cooked on the stove or in the oven, rice pudding, cakes, ice cream, and milk itself. At diagnosis, a child may tolerate some forms of allergenic foods without symptoms, so evaluation should consider this.

There are various treatment methods applied by pediatric allergy specialists to eliminate food allergy, such as allergen immunotherapy. These methods aim to activate the immune system to overcome the allergy using forms of milk or egg proteins that the child can tolerate. Close follow-up by a pediatric allergist is essential for these treatments.

Safe Feeding Recommendations for Children with Food Allergy

Safe feeding recommendations for children with food allergy include removing allergenic foods from their diet. All caregivers (grandparents, aunts, etc.) should be educated about the child’s allergies and made aware of which foods to avoid.

Milk and eggs, the most common allergens, are often ingredients in many recipes, so careful attention must be paid to the child’s diet. Packaged foods should always be checked for allergen labels.

In some cases, even trace amounts of the allergen or inhaling vapors released during cooking of the allergenic food can trigger symptoms.

Safe alternative nutritious foods should replace allergenic foods. Foods with adequate calories and nutritional value to support the child’s growth should be selected with the help of a dietitian. If the child attends school, the school administration should also be informed to ensure a safe eating environment at school.

Anaphylaxis and First Aid in Food Allergy

If a child or infant has a severe food allergy, accidental exposure to the allergenic food can trigger anaphylaxis.

Anaphylaxis can occur with any food that causes allergy, such as cow’s milk, eggs, and nuts. Anaphylaxis is especially more frequent and severe with nuts. Children and adults with food allergy accompanied by asthma, especially if asthma is not well controlled, are at higher risk for anaphylaxis.

For infants and children with food allergy who have previously experienced anaphylaxis, an adrenaline auto-injector containing epinephrine should be prescribed to manage accidental exposure. Additionally, if the child has accompanying asthma, a history of nut allergy-related hives, or only skin involvement, or if the family lives far from a health center, an adrenaline auto-injector should also be prescribed.

First Aid in Food-Related Anaphylaxis

During first aid, the patient should be placed in a position lying down with the head turned to the left side to keep the airway open, and breathing should be monitored. If the patient has a known allergy and the auto-injector is available, adrenaline should be administered intramuscularly through clothing into the outer upper thigh while the patient is lying down. Raising the legs slightly while lying down increases blood flow to the heart and brain. After administering adrenaline, emergency services (e.g., 112) should be called, and the patient should be taken to a healthcare facility immediately.

Treatment of Anaphylaxis in Food Allergy

The first drug to be given to infants or children in food-related anaphylaxis is adrenaline. In the hospital, the adrenaline ampule should be broken and given at a dose appropriate to the child's weight (0.1 mg/kg). If there is low blood pressure, fluid support is essential. Airway patency should be maintained and oxygen should be given if possible. If the patient is in an ambulance or health facility, intravenous access should be established for fluid administration.

If the patient has low blood pressure, intravenous fluid therapy should be provided. If there is respiratory distress or difficulty breathing due to lung-related causes, salbutamol nebulization should be given via mask. Other medications such as antihistamines and corticosteroids should also be administered.

If there is insufficient response to adrenaline for life-threatening symptoms, additional doses can be given as needed. If there is no improvement after three consecutive intramuscular adrenaline injections, the patient should be admitted to an intensive care unit for close monitoring.

Is It Possible to Prevent Food Allergy in Children?

Modifying some environmental factors may help prevent food allergy in children.

Some studies show that in children at high risk for allergy due to parental allergic diseases, applying moisturizers early in infancy to prevent atopic eczema also reduces the development of food allergy in later months and years.

Therefore, early and effective treatment of eczema prevents the infant’s skin from exposure to food allergens and sensitization. Other studies have shown that introducing a variety of foods from different food groups after starting complementary feeding within the first year reduces the risk of food allergy later on.

Additionally, during pregnancy, a diet rich in fiber, vitamins, minerals, fresh vegetables and fruits, antioxidant-rich olive oil, raw nuts, and whole grains, while avoiding processed red meat and sugary packaged foods, has been associated with a reduced risk of food allergy.

How to Recognize If a Baby Has a Food Allergy?

Signs that a baby may have a food allergy are related to symptoms experienced after eating.

If symptoms suggestive of food allergy occur, the baby should be evaluated by a pediatric allergist, and necessary tests should be performed for an accurate diagnosis.

Common allergic reactions include redness and swelling (hives) on the skin of the face, arms, legs, trunk, or neck; itching in affected areas or widespread itching; facial swelling; or atopic dermatitis rashes. Hives or eczema-related rashes may be localized or spread widely over the body.

Respiratory symptoms may include sneezing, nasal itching, hoarseness, difficulty swallowing, shortness of breath, and persistent coughing.

Gastrointestinal symptoms can include severe abdominal pain, vomiting, and, rarely in infants, bloody stools or diarrhea as signs of allergy.

Cardiovascular symptoms such as low blood pressure, dizziness, fainting or feeling faint, and palpitations can also occur.

To suspect allergy in these sudden symptoms, there must be prior consumption of a suspected food.

In exclusively breastfed infants, eczema or bloody, mucous stools may appear due to the allergenic food consumed by the mother.

Does Food Allergy Resolve on Its Own?

Whether a food allergy resolves on its own depends on the type of food causing the allergy. For example, recent studies show that the rate of resolution for cow’s milk and egg allergies is around 50% by the time the child reaches 5 years old. If the allergy is caused by nuts, this rate is about 20%. Some fish and wheat allergies have also been shown to resolve over time.

Which Doctor Should Be Consulted for Food Allergy?

For food allergy in children, a Pediatric Allergy Specialist should be consulted. The most appropriate department to address allergic complaints in children is the Pediatric Allergy and Immunology Department, and the best specialist is a Pediatric Allergist. Specialists in this department diagnose and treat allergic diseases such as childhood asthma, allergic rhinitis, urticaria, eczema, drug allergies, and food allergies.

A Pediatrician who successfully completes a subspecialty exam in Pediatric Allergy and Immunology can train for several years to follow children and adolescents with allergic diseases and immune system disorders in both outpatient and inpatient settings, receiving training from experienced mentors.

After three years of training, they earn the title of Pediatric Allergy and Immunology Specialist. After obtaining this title, they continue to work intensively and see patients in this field.