06 Nov Does my child have food intolerance or food allergy?

Dr Dr Ben – a paediatrician working in Cape Town.

I’ll never forget the day my oldest daughter tried tomatoes for the first time. We were celebrating a family birthday with a picnic at a beautiful spot on Table Mountain. My daughter who was one year old at the time put a few baby tomatoes in her mouth and soon thereafter started vomiting profusely. She had been completely well minutes before.

Reactions to certain foods are fairly common but may be caused by food intolerance rather than food allergy. Some of the physical symptoms in both food allergy and intolerance may be very similar. So what’s the difference? And does it matter?

Untoward reactions to food can be divided into those that are immunologic (involving the immune system), and those that are non-immunologic. The food allergies belong to the first and the intolerances belong to the second group.

In food allergy there is an overreaction of the body’s immune system to a food protein. The food allergies can be further divided into those that are Immunoglobulin E (IgE) mediated (typically causing reactions within minutes to two hours after ingestion) and those that are non-IgE mediated. The non-IgE mediated reactions may not present quite as fast as the IgE mediated and the symptoms are often isolated to the gastrointestinal tract and or skin. In contrast the IgE mediated reactions may involve a number of body systems such as the lungs, circulatory, digestive system and skin and may be life threatening. Foods that have been associated with food allergy include peanuts, tree nuts, milk, fish, shellfish, eggs, sesame, wheat and soy. Even a tiny trace of a protein may cause an allergic reaction in a susceptible individual.

Food intolerance is a chemical reaction that some people have after eating certain foods. The symptoms of food intolerance are often not as serious and are often limited to the digestive system. Often a tiny amount of the offending food does not cause a reaction but in increasing amounts of exposure the symptoms appear. A few examples of foods and related substances that have been associated with intolerance include tea and chocolate (theobromine), berries and fish (histamine), tomatoes and plums (tryptamine), cheeses and tomatoes (tyramine), banana and tomato (serotonin).

What are the symptoms of food allergy and a severe life threatening food allergy?

Some of the more common symptoms of food allergy include itching and swelling around the mouth, swelling of the face or eyes, itching and watery eyes, skin rashes including hives (urticaria), breathing difficulties and wheeze, running nose, nausea and vomiting, diarrhoea and cramping of the stomach.

A life threatening food allergy may involve an acute reaction to food or other substances that causes amongst others, difficult, noisy or wheezy breathing or persistent cough, tongue swelling or tightness in the throat and/or hoarse or difficulty talking, dizzy spell or collapse and becoming pale and weak. This is a life threatening medical emergency. Contact emergency medical services immediately.

There are allergies in my family, is this important?

There is an increased risk of allergy in individuals who have family members with allergies. Discuss the specific risks for your child with your paediatrician, paediatric allergologist or dietician with special interest in allergies.

How do I know which food caused the symptom?

This is done under the guidance of your paediatrician or paediatric allergologist. Finding the offending allergen can be fairly easy if the symptoms develop immediately after eating a specific food type but if the there is a delay in symptoms it can be a bit more tricky to ascertain which food caused the reaction. Your doctor may ask you to keep a food diary. In this diary you will document specific food types and associated symptoms. After some time a pattern will help to identify the culprit. In addition to this removing suspect foods from the diet for two weeks and then reintroducing them one at a time may help identify the problem food. Again this must be done under the direct guidance and instruction of your doctor. Skin prick testing using extracts from particular foods as well as allergy blood tests will help your doctor confirm the offending food or foods. 

If my child has a reaction to a certain food does that mean we have to avoid the particular food for life?

No, your doctor will ascertain whether or not the reaction was an allergy or food intolerance. He or she may then advocate re-introducing the offending food in small amounts in order to induce tolerance .This must be done under your doctor’s supervision and guidance. 

So what do I do to prevent allergies in my child if he or she has never had any allergic symptoms?

During pregnancy: The majority of studies show that avoiding certain foods in pregnancy does not protect against allergic disease in the baby. Eat a balanced healthy diet during your pregnancy without avoiding specific foods.

Breastfeeding: It is best to exclusively breastfeed for the first 4-6 months of your baby’s life. Again, mom should eat a balanced diet without avoiding specific foods unless you have been instructed so by your doctor.

Introduce solids: Introduction of solids from a wide range of food groups including those known to be allergenic can be done from 4-6 months. Do not introduce solids before 4 months of age.

Special formulas: The use of special formulas has not been shown to decrease allergy in your baby.

Any new symptom after the ingestion of a new food stuff should be discussed with your local doctor. He or she will help to make a diagnosis and then formulate a careful management plan.

So as it turns out my daughter now eats tomatoes in small amounts (although they are not her favourite) with no further problems.