Food Allergies in Children: Symptoms, Testing and Management in the UK

Few things cause parents more anxiety than discovering their child has a food allergy. I have worked with hundreds of families across the NHS and in private practice, and I know first-hand how overwhelming that initial diagnosis can feel. Questions flood in: What can my child eat? Is nursery safe? Will they always have this allergy? In my experience, clear and accurate information is the single most powerful tool a parent can have. That is exactly what I want to provide in this guide to food allergies in children in the UK, covering everything from recognising the very first symptoms to navigating testing, treatment and everyday management.

Understanding Food Allergies in Children

A food allergy occurs when a child’s immune system mistakenly treats a harmless food protein as a threat. The body launches a defensive response, releasing chemicals such as histamine that trigger a range of symptoms. This is fundamentally different from a food intolerance, which does not involve the immune system and, while uncomfortable, is not life-threatening.

There are two main types of food allergy I see in clinical practice:

• IgE-mediated allergies produce rapid symptoms, usually within minutes to two hours of eating the trigger food. These are the reactions most people picture when they think of food allergies: hives, swelling and, in severe cases, anaphylaxis.
• Non-IgE-mediated allergies involve a different part of the immune system and tend to cause delayed symptoms, sometimes appearing several hours or even days later. These often affect the gut and skin, and are particularly common in babies with cow’s milk protein allergy (CMPA).

Some children experience a mix of both, which allergists refer to as a mixed IgE and non-IgE reaction. Understanding which type your child has is essential because it affects both how we test for the allergy and how we manage it. If you are introducing solids to your baby for the first time, my guide on healthy weaning and introducing solid foods covers how to approach common allergens safely during that important stage.

How Common Are Food Allergies in UK Children?

Food allergy rates in the UK have risen sharply over the past three decades. Research from the University of Manchester suggests that hospital admissions for food-related anaphylaxis in children have increased by roughly 700% since the 1990s. Current estimates indicate that between 7 and 8% of UK children have at least one diagnosed food allergy, with the highest prevalence in the under-fives.

Why is this happening? The honest answer is that we do not have a single explanation. Several factors are likely at play:

• The hygiene hypothesis, which suggests that reduced exposure to infections and microbes in early life may alter immune development
• Changes in gut microbiome diversity, influenced by diet, antibiotic use and birth method
• Previous guidance that advised delaying the introduction of allergenic foods, which we now know may have increased risk rather than reduced it
• Greater awareness and improved diagnostic methods, meaning more allergies are identified today than in previous decades

These rising numbers mean that food allergies in children are no longer rare. They are a significant public health concern, and every parent, teacher and childcare professional should have a basic understanding of how to recognise and respond to allergic reactions.

The Most Common Food Allergens in Children

Under UK food law, 14 major allergens must be declared on food labels and in catering settings. However, the vast majority of childhood allergic reactions are caused by a smaller group of foods. In my clinical work, I see the same culprits again and again.

Cow’s milk protein allergy is the most common food allergy in UK infants, affecting an estimated 2 to 3% of babies. It is important not to confuse this with lactose intolerance, which is extremely rare in young children and involves the inability to digest lactose sugar rather than an immune response to milk protein. If your child has been diagnosed with CMPA, ensuring adequate calcium and calorie intake becomes a priority. My article on toddler nutrition for 1 to 3 year olds offers practical guidance on meeting nutritional needs at this critical stage.

Peanut allergy has attracted significant attention in recent years. The landmark LEAP study demonstrated that early introduction of peanut (from around six months, in age-appropriate forms) significantly reduced the risk of developing peanut allergy in high-risk infants. This finding has fundamentally changed the advice we give to parents.

Symptoms of Food Allergies in Children

Recognising the symptoms of a food allergy in a child can be straightforward in some cases and surprisingly tricky in others. IgE-mediated reactions tend to be dramatic and quick. Non-IgE-mediated reactions can be subtle and easily mistaken for other conditions.

Rapid-onset (IgE-mediated) symptoms

• Skin: hives (urticaria), redness, itching, swelling of the lips, face or eyes
• Gut: nausea, vomiting, abdominal pain, diarrhoea
• Respiratory: runny nose, sneezing, coughing, wheeze, difficulty breathing
• Cardiovascular: dizziness, feeling faint, collapse (a sign of anaphylaxis)

These symptoms usually appear within minutes and up to two hours after eating the allergen.

Delayed (non-IgE-mediated) symptoms

• Skin: eczema flares, persistent nappy rash
• Gut: reflux, colic-like symptoms, loose or mucousy stools, constipation, blood in stools, poor weight gain
• General: irritability, food refusal, unsettled behaviour

These symptoms can take hours to several days to develop, making it harder to link them to a specific food. In babies, non-IgE cow’s milk allergy is a frequent cause of persistent constipation or reflux symptoms that do not respond to standard treatment.

If your child has unexplained poor weight gain alongside gut symptoms, it is worth reading my guide on whether your child might be underweight, as undiagnosed food allergy is one of the less obvious causes I investigate in clinic.

When to Seek Emergency Help: Anaphylaxis

Anaphylaxis is a severe, potentially life-threatening allergic reaction that requires immediate emergency treatment. Every parent of a child with a diagnosed IgE-mediated food allergy must know how to recognise it and act fast.

Signs of anaphylaxis include:

• Swelling of the tongue or throat causing difficulty swallowing or breathing
• A persistent wheeze or hoarse voice
• Becoming pale, floppy or unresponsive
• Feeling dizzy or losing consciousness
• Widespread hives combined with breathing difficulty or a drop in blood pressure

What to do:

1. Use the child’s adrenaline auto-injector (such as an EpiPen or Jext) immediately into the outer thigh
2. Call 999 and say “anaphylaxis”
3. Lay the child flat with their legs raised (unless they are struggling to breathe, in which case sit them up)
4. If there is no improvement after 5 minutes, give a second adrenaline dose
5. Stay with the child until the ambulance arrives

According to NHS guidance on anaphylaxis, children prescribed adrenaline should always carry two auto-injectors. I cannot stress this enough: never leave the house, school or any activity without them. Practice using the trainer device so that you, your child and any regular carers feel confident acting quickly.

How Food Allergies Are Diagnosed and Tested in the UK

Getting a proper diagnosis is one of the most important steps in managing your child’s food allergy. I always tell parents: do not guess, and please do not rely on unproven tests bought online. Let me walk you through the evidence-based approach used across the NHS.

Step 1: A detailed clinical history

The most important diagnostic tool is a thorough conversation with your GP or allergy specialist. They will want to know exactly what your child ate, how long symptoms took to appear, what the symptoms looked like and how long they lasted. Keeping a food and symptom diary for two to four weeks before your appointment is enormously helpful.

Step 2: Allergy testing

For suspected IgE-mediated allergies, your doctor may arrange:

• Skin prick testing (SPT): A tiny drop of allergen extract is placed on the forearm and the skin is gently pricked. A raised wheal indicates sensitisation. Results are available within 15 to 20 minutes.
• Specific IgE blood test: A blood sample is sent to the laboratory to measure IgE antibodies against specific foods. This is useful when skin testing is not possible, for example if the child has severe eczema or cannot stop antihistamines.

For suspected non-IgE-mediated allergies, there is no reliable skin or blood test. Diagnosis relies on:

• Elimination diet: The suspected food is removed from the child’s diet (or the breastfeeding mother’s diet) for two to six weeks under dietetic supervision.
• Supervised reintroduction: The food is then reintroduced in a structured way to see if symptoms return.

According to NICE clinical guideline CG116 on food allergy in children, GPs should be able to diagnose and manage most non-IgE-mediated food allergies in primary care, referring to specialist allergy services only when the diagnosis is uncertain, the child has multiple food allergies or there is a history of severe reactions.

Tests to avoid

I feel it is my duty to warn parents about unproven allergy tests that are widely marketed in the UK. These include IgG blood tests, hair analysis, kinesiology and Vega testing. None of these methods have scientific evidence to support their use in diagnosing food allergies. They frequently produce false results, leading to unnecessary dietary restrictions that can harm a child’s growth and nutritional status.

Managing Your Child’s Food Allergy Day to Day

Once a food allergy is confirmed, the cornerstone of management is strict avoidance of the trigger food. This sounds simple enough, but in practice it requires constant vigilance and forward planning.

Reading food labels

UK food labelling regulations require that the 14 major allergens are highlighted (usually in bold) in the ingredients list of all pre-packed food. Get into the habit of reading labels every single time you buy a product, even ones you have purchased before, as manufacturers can change recipes without notice. “May contain” warnings are voluntary, not regulated, so discuss with your child’s allergist how to interpret these based on your child’s level of sensitivity.

Cooking and eating at home

Home is the safest environment for a child with food allergies because you have full control over ingredients. However, cross-contamination is a real risk if other family members eat the allergen. Simple measures include using separate chopping boards and utensils, thorough handwashing and cleaning surfaces with soap and water (alcohol-based wipes do not remove food proteins effectively).

If you are looking for practical ideas for safe, nutritious meals, my articles on cooking with children and healthy snacks for children include tips that can be easily adapted for allergen-free diets.

Eating out and social events

Restaurants, cafés and takeaways in the UK are legally required to provide allergen information for all the dishes they serve. I advise parents to speak directly to the chef or manager rather than relying solely on written menus or apps. Birthday parties, playdates and family gatherings require advance communication. Most other parents are understanding once the situation is explained clearly.

Nutritional adequacy

Eliminating one or more food groups can put a child at risk of nutritional deficiencies. This is particularly relevant for children avoiding milk (calcium, iodine, vitamin B12), egg (protein, B vitamins) or wheat (fibre, B vitamins, iron). I strongly recommend that any child on an allergen-free diet is reviewed by a registered paediatric dietitian who can assess intake and recommend appropriate substitutes or supplements. Children avoiding multiple foods may also benefit from guidance found in my article on getting children to eat vegetables, as broadening the range of accepted safe foods helps maintain good nutrition.

Emotional wellbeing

Living with a food allergy can affect a child’s mental health and self-esteem. Feeling different at mealtimes, anxiety about accidental exposure and being excluded from food-related activities can all take a toll. Talk openly with your child about their allergy in an age-appropriate way. My guide on body image and self-esteem in children includes strategies for building resilience and confidence that apply well to children managing chronic health conditions, and you may also find helpful approaches in my article on emotional eating in children.

Food Allergies at School and Nursery

Starting nursery or school is a major milestone for any child, and it brings an additional layer of planning for families managing food allergies. Under the Children and Families Act 2014, schools in England have a duty to support pupils with medical conditions, including food allergies.

Here is what I recommend to every family I work with:

• Request an Individual Healthcare Plan (IHP): This document, agreed between parents, the school and the child’s medical team, outlines the child’s allergens, symptoms to watch for, medication details (including where adrenaline auto-injectors are stored) and emergency procedures.
• Meet with school staff: Ensure that all relevant staff members (class teacher, teaching assistants, lunchtime supervisors, catering team) are aware of the allergy and trained to recognise and respond to a reaction.
• Provide medication: Supply the school with clearly labelled, in-date adrenaline auto-injectors. Many schools now also hold spare “generic” adrenaline pens for emergency use, as permitted under UK law since 2017.
• Discuss food policies: Talk to the school about their approach to allergens in the canteen, at snack time, during cooking lessons and at events such as bake sales or celebrations.
• Empower your child: Teach your child to recognise their allergens, to say no to food they are unsure about and to tell an adult immediately if they feel unwell. Even very young children can learn these skills with practice.

The Royal College of Paediatrics and Child Health allergy care pathway provides useful resources for both families and healthcare professionals navigating the referral and management process.

Will My Child Outgrow Their Food Allergy?

This is the question I hear most often, and the answer depends very much on the specific allergen and the type of reaction involved.

The good news is that many children do outgrow certain food allergies. Around 75 to 80% of children with cow’s milk or egg allergy will tolerate these foods by the time they start school. Soya and wheat allergies also have relatively high resolution rates. This is why regular review by your child’s allergy team is so important; they can arrange supervised food challenges at the right time to check whether the allergy has resolved.

Unfortunately, allergies to peanuts, tree nuts, fish and shellfish are more likely to persist. Only around 20% of children with peanut allergy and roughly 10% of those with tree nut allergy will outgrow it. However, even in these cases, the severity of reactions can change over time, and ongoing research into oral immunotherapy (OIT) is offering hope. OIT involves giving gradually increasing doses of the allergen under strict medical supervision, with the aim of raising the threshold at which a child reacts. The treatment Palforzia, approved by NICE for peanut allergy in children aged 4 to 17, is one such example, though availability on the NHS remains limited.

Regardless of the type of allergy, I advise parents to never reintroduce a food at home without medical guidance. Supervised food challenges are carried out in a clinical setting where staff are trained to manage any reaction that may occur.