Food allergies in children: your FAQs answered by a specialist

Written in association with: Professor Adam Fox
Published: | Updated: 06/03/2019
Edited by: Emily Lawrenson

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 hay fever, 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 hay fever or asthma.

Read more: Childhood 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 the chances of your baby developing an allergy. Aim to breastfeed, if possible, for six 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.

By Professor Adam Fox
Allergy & immunology

Adam read Medicine and Neuroscience at Cambridge University before completing his clinical training at University College, London. After specialist training in Paediatric Allergy in 2006, he was one of the founding consultants of what is now one of Europe's largest specialist Allergy services, at St Thomas' Hospitals, London. Adam spent 9 years as clinical lead for Allergy (Adult & Paediatric) at Guy's & St Thomas' Hospitals, during which time the service was recognised as an International Centre of Excellence by both the World Allergy Organisation and GALEN (European Asthma & Allergy Network).

He is also a Professor of Paediatric Allergy at King's College London and the founding Director of the KCL Allergy Academy, a postgraduate educational programme, which was a finalist at the BMJ Awards in 2018. Adam chaired the UK Department of Health National Care Pathway for Food Allergy in Childhood and was a member of the National Institute of Healthcare and Clinical Excellence (NICE) clinical guideline development group for the assessment and diagnosis of food allergy in children.

He has been an expert committee member on two MHRA specialist groups and a NICE Health Technology Appraisal and was appointed a NICE non-specialist guideline chair in 2021. He was senior author of the iMAP (International Milk Allergy in Primary Care) guideline, which was awarded the Allergy UK Innovation award in 2018. He previously represented Paediatric Allergy on the NHSE Specialist Paediatrics Clinical Reference Group and chaired the Paediatric Committee of the British Society of Allergy & Clinical Immunology (BSACI). He was elected as BSACI President, the first Paediatrician to hold this position, from October 2018 until 2021, after which he took on the role of Chair of the National Allergy Strategy Group from July 2022.

As part of this, he jointly chairs the Expert Advisory Group for Allergy with the Department of Health & Social Care and is lead for the National Allergy Strategy. In 2024, Adam became only the second person to receive the BSACI Fellows Award in recognition of outstanding contribution to clinical allergy. Adam was awarded ‘Paediatric Allergist of the Year’ from Allergy UK in 2007. His doctoral thesis on peanut allergy received the Raymond Horton Smith prize from Cambridge University in 2012 and he was included in The Times ‘Britain’s 100 Best Children’s Doctor’s’ (2012).

Adam received the William Frankland Award for Outstanding contribution to Allergy from the British Society of Allergy & Clinical Immunology in 2015 and a National Clinical Excellence award from the UK Department of Health in 2016 and 2020. In 2024, Adam became only the second person to receive the BSACI Fellows Award in recognition of outstanding contribution to clinical allergy. Adam has lectured around the world, made numerous documentaries, published over 100 research articles including in top medical journals (NEJM, BMJ, Pediatrics) and is a regular contributor on ITV ‘This Morning’ and BBC Morning Live.

Adam’s private practice, Allergy London was awarded 'Best Allergy Clinic - London' in the 2019 Global Health & Pharma Private Healthcare Awards and Best Allergy Testing Specialists in the 2020 Private Healthcare Awards. He was also recognised by Doctify for 'Excellent Patient Experience' in 2018 and was one of a small number of specialists to receive the ‘Top Doctors award’ in 2018 and again in 2022 from Top Doctors website, voted for by other doctors, asked to nominate who they would choose to go to.

He was also listed in the most recent ‘The Tatler Doctors List’ (2013) of the best 250 UK private medical consultants. Together with two colleagues he established The Food Allergy Immunotherapy Centre at Great Ormond St Hospital in 2021, where he initiated the first patient in the world, outside of the US, on Palforzia (the first licenced food allergy desensitisation product) in October 2021.

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