Part of the London Allergy Clinic
Diagnosis & Specialist Care of Allergy - Since 1982
Peanut allergy is one of the most common — and most talked-about — food allergies in childhood. In the UK, it affects around 2% of children (approximately 1 in 50), and unlike many childhood food allergies, it tends to be persistent: only around 1 in 5 children with peanut allergy will outgrow it, usually by the age of ten. For most children, a diagnosis of peanut allergy means learning to manage it as a long-term condition.
Tree nut allergies — to nuts such as almonds, cashews, walnuts, hazelnuts and others — are a separate category, and are less common than peanut allergy. However, around 30 to 40% of children with peanut allergy will also have an allergy to at least one tree nut, so both are worth assessing together.
Getting a clear, confirmed diagnosis matters enormously — both to ensure your child is properly protected, and to avoid unnecessary restriction when a suspected allergy may not be present at all.
Early weaning trials
A landmark clinical trial called the LEAP study (Learning Early About Peanut Allergy), led by Professor Gideon Lack at King's College London, found that introducing peanut into the diet of high-risk babies from around four to six months of age reduced the risk of developing peanut allergy by 81%.
This fundamentally changed the guidance on early allergen introduction — and it's one of the reasons specialist advice for high-risk babies (particularly those with eczema or egg allergy) is so important to get right.
Peanuts and Tree Nuts — An Important Distinction
Many parents are surprised to learn that peanuts are not actually nuts at all — they are legumes, from the same plant family as lentils and chickpeas, and they grow underground. Tree nuts (such as almonds, cashews, walnuts, Brazil nuts, hazelnuts, pistachios and pecans) are botanically quite different.
This distinction matters clinically. A child with peanut allergy does not automatically have an allergy to tree nuts, and vice versa. However, co-existing allergies are common enough that both should be assessed, and cross-contamination between peanuts and tree nuts in food manufacturing means that in practice, families often need to manage both.
Symptoms
Peanut and tree nut allergies are almost always IgE-mediated, meaning symptoms appear quickly — usually within minutes of exposure. These can include:
• Hives (urticaria) — raised, itchy welts on the skin
• Swelling, particularly around the mouth, lips, face or throat
• Tingling or itching in the mouth
• Vomiting or stomach pain
• Runny nose, sneezing or watery eyes
• In severe cases, anaphylaxis — a serious, potentially life-threatening reaction affecting breathing and circulation
If your child has shown signs of a severe reaction — significant facial swelling, difficulty breathing, or collapse — please seek emergency medical attention via 999 or A&E, and speak to your GP about an adrenaline auto-injector (such as an EpiPen) before seeking a specialist appointment.
Who Is At Higher Risk?
Certain children are more likely to develop peanut or nut allergy. The strongest risk factors, based on current evidence, are:
• Eczema, particularly moderate to severe eczema in infancy
• Egg allergy — children with egg allergy have a significantly higher risk of also developing peanut allergy
• A family history of allergic conditions (asthma, eczema, hay fever, food allergy)
If your baby has eczema or has already been diagnosed with egg allergy, specialist advice on the safe introduction of peanut and other allergens is particularly important.
What We Assess
When you bring your child to see us about a suspected nut or peanut allergy, we will take a detailed clinical history and consider:
• The nature, timing and severity of any previous reactions
• Which specific nuts or nut products were involved
• Whether symptoms suggest peanut, tree nut, or both
• Relevant medical history, including eczema and other allergic conditions
• Appropriate allergy testing — skin prick testing and/or specific IgE blood tests — to confirm sensitisation
We will provide a clear written report, a personalised management plan, and guidance on reading food labels, avoiding cross-contamination, and managing reactions should they occur.
About Our Approach
Both Dr Tammy Rothenberg and Dr Emily Derrick have extensive experience in the assessment and management of nut and peanut allergy in babies and children. They take a thorough, evidence-based approach — and importantly, a clear diagnosis works both ways: confirming an allergy when it is present, and ruling one out when the evidence doesn't support it, to avoid unnecessary dietary restriction.
Our specialist Paediatric Allergy Dietitian, Misbah Primett, works alongside our consultants and can provide tailored dietary guidance — including advice on safe allergen introduction for high-risk babies, food labelling, and nutritional support for children on restricted diets.
Related Pages
Frequently Asked Questions
If your child has had a reaction to a nut or peanut product, or you have concerns about their risk, a specialist assessment will give you clear answers and a practical plan.
Call us, email us or WhatsApp us — a real person will always respond, six days a week.
📞 0207 637 9711
✉ enquiries@londonallergyclinic.com
Mon–Sat, 9am–7pm