Food Allergies in Children
As parents, we do our best to provide our children with the best nutrition with a wide range of foods for variety and balance. However, there are times when kids develop reactions after eating certain types of food – a result of food allergies or intolerances.
What is a food allergy?
A food allergy is an abnormal response of the body’s immune system to food. The immune system normally works to protect us against harmful microbes. If the immune system is triggered by food, a food allergy develops.
There are some common foods that may trigger an allergic reaction in children. These include common ingredients such as eggs, milk, peanuts, tree nuts like almonds and cashews, soy and wheat. Genetic predisposition is the most common reason why some children develop a food allergy. If either parent or both parents have food allergies, respiratory allergies or eczema, then the child has an increased risk for developing a similar allergic condition. Children with eczema also have a higher risk of developing food allergies.
Common allergy foods
Almost any food can cause an allergy, though the most common foods that are high on the offender list include:
An allergy to cow’s milk is one of the most common childhood food allergies. However, most children eventually outgrow it by the time they are 3 – 5 years old.
Egg allergy is caused by an allergic reaction to egg protein found mostly in the egg white. Since it’s impossible to eat an egg yolk that does not have any traces of egg whites, those allergic to egg protein will have to stay away from eggs altogether.
An allergic reaction to soy is often picked up when an infant needs to switch to a soy-based formula after a suspected cow milk allergy. Most children outgrow their soy allergy, but some remain allergic into adulthood.
Wheat and gluten
An allergy to wheat may be seen when a baby is given a wheat-based cereal during the transition to solid food. Bread and pasta are among other common wheat-based foods given to young children that may trigger an allergic reaction. Some children may have a specific reaction to a protein found in wheat and some other foods called gluten.
Shellfish is one of the most common food allergens among older Asian children. Fish allergy is less common but may still occur.
Even though allergy to peanut is more common in the West than in Asia, it is however, one of the most common contributors of severe allergic reactions in Singaporean children.
Tree nuts are nuts enclosed in hard shells, including walnuts, pecans, cashews, Brazil nuts, almonds and hazelnuts. A person can be allergic to all tree nuts or only to a few of them.
Symptoms of food allergies in children
The most common symptoms of food allergy are skin symptoms. Within minutes to a few hours after eating the food, the child can develop hives – red itchy, raised rashes that vary in size, in any part of the body. Some children can also develop a swell in the lip or the area around the eye.
Food allergies may also cause more severe symptoms such as breathing difficulties, swelling in the throat, swelling of the tongue, or even a reduction in blood pressure which may cause a child to look pale or feel faint.
Food intolerance in children
Food intolerance is unacceptance of food by the body due to physiologic reasons. The most common type of food intolerance is lactose intolerance. This is because the body lacks the enzyme lactase, which helps to break down lactose, the main carbohydrate in dairy products such as fresh milk and cheese. People with lactose intolerance may develop abdominal pain, bloating, or diarrhoea after consuming dairy.
Food intolerance can also be caused by reactions to naturally occurring chemicals in food. A common example is developing insomnia, restlessness or jitters after taking coffee or other caffeinated drinks. Others may react to food additives such as monosodium glutamate (MSG). They may experience headaches, hot flushes and even chest pain after consuming food containing MSG.
How do you differentiate between a food allergy and food intolerance?
A food allergy is more commonly seen among infants and young children while food intolerances develop usually towards adolescence and even adulthood.
Children with food allergy can develop symptoms even when exposed to just a small amount of the culprit food. In contrast, the symptoms of food intolerance are dose-related. People with food intolerances are more likely to develop symptoms if they consume a large amount of the food or if they eat the food frequently.
Food allergies can result in severe, life-threatening symptoms. Anaphylaxis is a serious allergic reaction that can cause breathing difficulties, loss of consciousness, and reduction in blood pressure. Without proper treatment, it can be fatal. Anaphylaxis does not occur in food intolerance.
Diagnosing food allergies in children
When you bring your child for a consult, the paediatrician will ask detailed questions about your child’s medical history, the types of food(s) that trigger a reaction, what symptoms develop, and how long it takes for the symptoms to develop after food exposure or consumption.
Depending on your child’s medical history, an allergist can perform or request for any of the following tests to confirm the diagnosis of food allergy:
- Skin prick tests
- IgE (immunoglobulin E) bloods tests (to test for allergen antibodies formed in the presence of allergies)
- Oral food challenge
What is a skin prick test?
A skin prick test is used to identify allergy-causing substances or allergens. In this test, the allergens are inserted into the skin layers and observed for allergic reactions.
When an allergen is inserted into the skin, the body treats it like a foreign substance and produces antibodies to fight against it. The binding of the allergen to the antibody release chemicals such as histamine that triggers an allergic reaction.
How is a skin prick test conducted?
Before conducting the skin prick test, your doctor will review your child’s medical history and perform a physical exam.
A small drop of the suspected allergen is placed on the skin on the child’s back or forearm. Next, the top surface of the skin is scratched lightly with a small needle. The skin is then observed for signs of allergic reactions.
The results are obtained within 15 minutes. If your child is allergic to one of the substances tested, they will develop a red, swollen, and itchy bump at the prick site.
How can you prepare for the test?
Medications can interfere with results; hence your child should not be taking any antihistamine medications or cough mixtures for 5 days before the test.
Is the test safe for children?
The skin prick test is safe and painless. Some may find it slightly irritating. The skin reaction subsides on its own within a couple of hours. For children who experience discomfort from the itch, oral antihistamine or mild topical steroid cream may be prescribed.
With a skin prick test, different allergens can be identified in one go. Information from skin prick tests may help your child’s doctor develop an allergy treatment plan.
Treating food allergies in children
The main treatment for food allergy is to avoid the food that triggers the allergic reaction. It is important to read the ingredient labels on food products. Food products that contain the culprit food, even if it is only in small amounts, should not be given to your child. When eating out at restaurants, notify your servers about your child’s allergy. Inform them that even the pots, pans and utensils used to prepare your child’s food should not be contaminated with the culprit food.
It is also important to inform key people such as child care providers, school personnel, and the parents of your child’s friends, about your child’s food allergy. Explain to them how to recognise the symptoms of an allergic reaction, and what to do if your child has an allergic reaction. A written action plan describing how to care for your child is useful.
What to do during an allergic reaction?
There are several things you can do if you suspect that your child is having an allergic reaction.
For mild symptoms, such as rashes, hives, watery or itchy eyes, over-the-counter antihistamines may be given, as advised by a doctor or pharmacist. Watch closely for any changes and seek medical care if symptoms worsen.
For severe symptoms, including abdominal pain, nausea or vomiting and difficulty breathing, an epinephrine injection must be administered immediately.
Have your child lying down flat, with their legs elevated and their body kept warm. Help them to sit up or lie on their side if they are having trouble breathing or are vomiting. Make arrangements to take your child to the emergency department right away, even if their symptoms improve or resolve.
If your child has been prescribed an epinephrine autoinjector or if your child has severe allergies, ensure your child is taught how and when to use the epinephrine autoinjector. It is also important to ensure they carry it with them at all times.
When should I see a doctor?
It is best to consult a doctor if you suspect that your child has a food allergy. If your child develops severe allergic reactions such as breathing difficulties, appears pale, or loses consciousness, do not delay going to the nearest Accident & Emergency (A&E) department.