Food allergies in children: your FAQs answered by a specialist

Food allergies in children are becoming increasingly common, with the number rising as time goes by. Food allergies, which 30 years ago were considered unusual, are now becoming more widespread, affecting an estimated 5-6% of young children and 1-2% of adults.

Nowadays it seems that we all know someone who has a food allergy, and if you have a history of allergies in the family, it’s natural that you might worry about your child developing one themselves. The good news is that as the numbers increase, so does our awareness – but it’s important to know what the red flags are, and what to watch for, giving you an idea if the symptoms indeed point to an allergy. Dr Adam Fox, a leading paediatric allergist from Allergy London, is here to answer some of the most frequently asked questions about food allergies in children.

1. Are allergies genetic?

Specific allergies themselves are not inherited, but the tendency to develop allergies and allergic problems (e.g hayfever, asthma, eczema) can be inherited from one or both parents. Just because you are allergic to shellfish, for example, does not mean that your child will be automatically, but it does mean that they have a chance of inheriting an allergic tendency. There is also the chance that a child will develop an allergy with no genetic link, as allergies may also be influenced by environmental factors.

2. My child has eczema, should I be worried about a food allergy developing?

All atopic diseases (hay fever, asthma, eczema, food allergies) are related to one another, and food allergies are most common amongst babies who have eczema. Children who are atopic often go through a process we call the ‘allergic march’, which is a progression of the related conditions. This often starts with eczema when very young, which predisposes food allergies. Children often outgrow their eczema and food allergy, but on occasion these conditions can give way to respiratory allergy, such as hayfever or asthma.

3. What are the most common food allergies in children?

The most common types of immediate reaction food allergy are egg, milk, nuts, fish, sesame and shellfish. Soy, wheat, and kiwi are also rather frequent, but for delayed type allergies (where symptoms are not seen immediately after the food is ingested), the most common culprits are milk and soy.

4. What’s the difference between an allergy and an intolerance?

A food allergy causes an immune system reaction which can affect various organs in the body. Food allergies can be serious and a reaction can be life-threatening. Intolerances, on the other hand, are generally less serious and are more often related to problems digesting food. There are two types of allergy, the first being immediate allergy, which causes rash, swelling, and hives to develop within minutes of the food being eaten, and delayed allergies. Delayed allergies can cause eczema to develop, or symptoms such as reflux, colic, and diarrhoea – the latter three sometimes being seen as symptoms of intolerance, too. If you are worried about any of these symptoms or notice them in your child, you should visit your GP.

5. If my baby is allergic to one food, will they also be allergic to others?

It’s true that having one allergy often increases the risk of other allergies being present or developing. Certain allergies are commonly experienced together, for example egg and peanut, or peanut with treenuts and sesame.

6. If I eat nuts while pregnant, is there a chance my baby will develop an allergy?

There is no need to avoid nuts during pregnancy, or while breastfeeding. Eating nuts during this time has no influence on your baby developing a nut allergy.

7. Is there any way to protect my baby from developing an allergy?

Avoiding certain foods during pregnancy or while breastfeeding does not seem to make any difference in increasing chances of your baby developing an allergy. Aim to breast feed, if possible, for 6 months exclusively. Evidence is beginning to emerge that introducing complementary foods, in particular eggs and peanut, from 17 weeks onward, may be helpful in protecting against allergies to these foods developing.

8. Will my baby outgrow their allergy?

This sometimes depends on the allergy. Fortunately, children tend to outgrow allergies to milk, egg, soy, and wheat. On the other hand, allergies to peanuts, treenuts, fish and shellfish tend to continue through to adulthood.

Learn more about Dr Fox and Allergy London on his Top Doctors profile. If you are interested in discussing your child’s allergy symptoms and learning more about allergy testing, make an appointment with a specialist.