Nurturing healthy, happy bellies

What’s the difference between a food allergy and a food intolerance (or adverse reaction to food)?

Although they can look similar, food allergies and adverse food reactions are very different. It is important for parents to understand the difference.

A food allergy happens when your child’s immune system mistakes a food protein for something harmful and reacts to it. Even a very small amount of the food can trigger symptoms, and reactions can be serious. Allergic reactions can sometimes lead to anaphylaxis, a severe reaction that can affect breathing, blood pressure, and consciousness. This is a medical emergency.

An adverse reaction to foods, or food intolerance, does not involve the immune system. Instead, it usually happens when your child’s body has trouble digesting a certain food. They may cause tummy pain, bloating, wind, or diarrhoea, but they do not cause anaphylaxis. In short, intolerances can be uncomfortable, but they are not life-threatening.

If you’re unsure whether your child has a food allergy or adverse reactions to food, getting the right diagnosis can bring clarity and peace of mind.

IgE and non-IgE mediated food allergies – what’s the difference?

Not all food allergies behave in the same way. Broadly, they are divided into IgE-mediated and non-IgE–mediated food allergies.

IgE-mediated food allergies are the “classic” food allergies that most people think of. Reactions usually happen within minutes to 1–2 hours of eating the food and can include:

• Hives or swelling
• Vomiting
• Wheezing or breathing difficulties
• Anaphylaxis

These allergies can often be supported by blood tests or skin prick tests, alongside a careful clinical history.

Non-IgE–mediated food allergies cause delayed reactions, typically 2–24 hours after eating the food. Symptoms most often affect:

• The gut – abdominal pain, diarrhoea, vomiting, reflux, feeding difficulties
• The skin – eczema flares

They can sometimes cause other, less specific symptoms as well.  Importantly, blood tests and skin prick tests are not helpful for diagnosing non-IgE–mediated allergies.

Instead, diagnosis is based on a structured elimination and reintroduction process. The suspected food is excluded for 4 weeks, then reintroduced for 4 weeks. If symptoms improve during exclusion and then return on reintroduction, a non-IgE–mediated food allergy is diagnosed.

Understanding whether your child’s allergy is IgE or non-IgE mediated is crucial, as it affects how reactions present, how they are investigated, and how they are managed day to day.

How common are food allergies in children?

Food allergies affect around 1 in 10 children, with higher rates in infants and young children. The most common triggers include milk, egg, peanut, tree nuts, wheat, soy, and seafood.

If I suspect an allergy, when should I consult a doctor?

Any reaction involving hives, swelling, vomiting, breathing issues, or repeated reactions to the same food should be assessed by a doctor.

Signs of anaphylaxis may include:

In some cases, an allergic reaction can become severe and lead to anaphylaxis. This is a serious, potentially life-threatening reaction that needs immediate medical attention. Knowing the warning signs and acting quickly can help keep your child safe.

Signs of anaphylaxis may include:

Breathing and airway problems: A hoarse or croaky voice, trouble swallowing, a swollen tongue, shortness of breath, or noisy, difficult breathing.

Changes in circulation or alertness: Your child may look pale, become floppy, suddenly very tired, dizzy, or collapse. In severe cases, they may lose consciousness.

Sudden behaviour changes: A child may become unusually quiet, distressed, anxious, or “not themselves,” which can be an early sign of a serious reaction.

Should I cut food from my child’s diet?

I know food allergies can be very worrying, especially if they are causing your child discomfort or you are worried about them eating at school or social occasions. However, I would always recommend that you speak to a doctor before cutting anything from a child’s diet.

I see many children in my clinic unnecessarily avoiding foods they believe they are allergic to. Restricted diets can be nutritionally unsound, especially in growing children. As a paediatric allergy consultant, I can quickly diagnose acute allergies that may cause rapid reactions and provide a personalised management plan for your child, so that any changes you make are based on medical evidence.

How are childhood food allergies diagnosed?

First, I will have a chat with you and your child. This will help me understand the symptoms and take a careful, detailed medical history. Based on your child’s symptoms, I may recommend allergy testing such as skin prick testing or specific IgE blood tests (find out the difference). In some cases, a supervised food challenge or food diary may be recommended. Together, these assessments are the most reliable way to confirm a food allergy or confidently rule allergy out as the cause of your child’s symptoms.

How accurate are skin prick tests and blood tests?

These tests are helpful but not perfect. Results must be assessed alongside symptoms.

What is an oral food challenge, and is it safe?

An oral food challenge involves eating small amounts of a food under medical supervision. It is the most accurate way to confirm or rule out a food allergy and is performed safely in a clinical setting.

Can food allergies in children be treated?

There is no instant cure, but food allergies can be actively managed. Some children may be suitable for treatments such as immunotherapy under specialist care.

What is immunotherapy?

Immunotherapy, also known as densensitisation therapy, involves gradually introducing small amounts of an allergen to increase tolerance. It is not suitable for every child and must be supervised by an experienced specialist.

Can children outgrow food allergies?

Many children outgrow allergies to milk, egg, wheat, or soy. Peanut, tree nut, and seafood allergies are less likely to resolve but can still change over time.

How can I help manage my child’s food allergy?

After we identify food allergies, management typically includes avoiding confirmed allergens, reading labels carefully, maintaining an action plan, and ensuring that anyone involved in caring for your child knows what to do in an emergency.

As your child becomes more independent, it is important that they actively understand and manage their allergies.

How can my child eat safely at school or childcare?

Clear communication is absolutely key. Ensure that anyone involved in caring for your child understands which foods are problematic, how to identify them in ingredient lists, what symptoms look like, and how to manage reactions. Allergy action plans, staff education, and appropriate risk management are essential to helping children with food allergies participate safely in school and social settings.

Does my child need an adrenaline auto-injector or intranasal adrenaline?

Children at risk of anaphylaxis are prescribed an adrenaline auto-injector such as EpiPen  / Jext, or intranasal EURNeffy.  A pediatric allergy specialist will assess this risk, prescribe the most appropriate medicine, and provide training on when and how to use it. Both are emergency treatments for anaphylaxis and should be given immediately, followed by calling 999.

• Adrenaline auto-injector (e.g. EpiPen  / Jext): Injects adrenaline into the thigh muscle. Long-established, very reliable, but involves a needle, which some children and carers find stressful.
• Intranasal adrenaline (EURNeffy): Delivers adrenaline as a nasal spray. Needle-free, quick to give, and easier for some families and schools to use. Must be used exactly as prescribed and carried at all times.

Do you have expertise in the management and treatment of food allergies in children?

I have extensive experience in diagnosing and managing food allergies in children. I regularly see babies, children, and adolescents with suspected or confirmed food allergies as part of my specialist allergy clinics.

My approach is thorough and evidence-based, beginning with a detailed clinical history and, where appropriate, followed by allergy testing such as skin prick tests, specific IgE blood tests, and supervised food challenges. This allows me to accurately confirm food allergies and, just as importantly, to rule them out when they are not the cause of a child’s symptoms.

Alongside my private practice, I have developed and led a large paediatric allergy service within the NHS, caring for thousands of children with allergic conditions each year. I am a certified European Paediatric Allergist and have broad experience managing both mild and complex food allergy cases, including children at risk of severe reactions.

My focus is not only on diagnosis, but also on practical, family-centred management. I support families with clear allergy action plans, guidance on safe food introduction or avoidance, and advice for schools and childcare settings. My aim is to keep children safe while minimising unnecessary dietary restrictions and anxiety for families.