Food Allergy Testing in London

Our clinic diagnoses food allergies in infants, children, and adults using the three methods that allergy medicine trusts: skin prick testing, specific IgE blood testing, and supervised food challenges. The service is led by Professor Gideon Lack, whose LEAP and EAT studies changed how the world prevents food allergy.
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A food allergy diagnosis changes how a family shops, cooks, and eats. Getting it right matters as much as getting it quickly. We test for the foods that cause the majority of reactions in the UK, including peanut, tree nuts, egg, milk, sesame, fish, shellfish, wheat, and soya, and we interpret every result against your or your child’s clinical history rather than a number alone.
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Who food allergy testing is for

We test:

Babies and infants with suspected reactions to milk, egg, or first solid foods; testing is safe from the first months of life
Children with a history of reactions, or with eczema that raises their risk of food allergy
Families introducing allergens such as peanut where a sibling has a food allergy or the baby has severe eczema
Adults with new or unexplained reactions to food
Anyone who has been avoiding a food for years and wants to know whether the allergy is still present

The tests we use

Skin prick testing
A drop of allergen extract on the forearm, a gentle prick, and a measurable result within 20 minutes. Skin prick testing lets us test many foods in a single appointment and discuss the results with you the same day. It is well tolerated by young children.
Specific IgE blood testing
A single blood sample measures the antibodies your immune system has produced against individual foods. Blood testing is the right choice when eczema makes skin testing difficult, when antihistamines cannot be stopped, or when we need component testing to distinguish a true allergy from a cross-reaction.
Supervised food challenges
The definitive test. Under specialist supervision, your child eats gradually increasing amounts of the suspected food while we monitor for any reaction. A food challenge is how we confirm a diagnosis when other results are borderline, and how we prove an allergy has been outgrown, so a family can stop avoiding a food with confidence.

Food allergy or food intolerance

The distinction decides which test you need. A food allergy involves the immune system; reactions are rapid and can be severe, and it is diagnosed with the tests above. A food intolerance does not involve IgE antibodies; symptoms such as bloating or discomfort build slowly, and no blood or skin test can diagnose it. We advise on both, and we will tell you plainly when testing is not the right tool. High-street intolerance tests measuring IgG are not diagnostic and frequently lead families to restrict foods unnecessarily.

What to expect during your visit

What happens at your appointment

Consultation: a specialist takes a detailed history of reactions, diet, and family allergy
Testing: skin prick tests during the appointment, with blood tests taken the same day where needed
Results and plan: skin test results are discussed on the day; you leave with a written management plan covering avoidance, emergency treatment, and next steps
Follow-up: where a food challenge or retesting is recommended, we schedule it and manage the pathway
If your child takes antihistamines, they need to be paused before skin testing; our guide to stopping medications before testing explains the timings.

Why families choose us for food allergy testing

Professor Lack heads the Children's Allergy Service at Guy's and St Thomas' NHS Trust and is Professor of Paediatric Allergy at King's College London. The LEAP, EAT, and LEAP-Trio studies that his team ran are the reason global guidelines now recommend early allergen introduction. When your child's results need interpreting, that is the depth of expertise reading them.
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Testing is one part of a complete service: diagnosis, prevention advice for younger siblings, emergency planning, and treatment for confirmed food allergies, including oral immunotherapy.
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Pioneering research, personalised care

Our approach combines our team's groundbreaking research into the causes and treatment of allergies with deeply personalised care. As global leaders in allergy prevention and treatment, we're dedicated to transforming lives through early intervention and innovative therapies. From food allergies and asthma to eczema and anaphylaxis, we provide evidence-based treatments tailored to each patient's needs.
More About the LACK Clinic
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Eczema
“As far as our family is concerned, Professor Lack is a miracle worker. We trust his advice implicitly and are very lucky to have him as our daughter’s specialist.”
Eczema
28th Sept 2024
Eczema
verified patient

Common questions about allergy testing

How much does food allergy testing cost?

Fees depend on the tests your consultation identifies as necessary. Consultation and testing fees, and the insurers we work with, are listed on our fees and insurance page.

Can I get food allergy testing on the NHS?
Yes, through a GP referral to an NHS allergy clinic, and for many families that is the right route. Waiting times for specialist paediatric allergy services are often long. Families come to us when they want rapid access to testing, results, and a management plan from the same team.
Which food allergy test is best?

No single test is best for every situation; each answers a different question, and results only carry meaning alongside clinical history. Our guide to choosing between skin and blood testing explains how we decide, and how to read the results.

Should we test before introducing peanut?

For most babies, no; early introduction without testing is the evidence-based route. For babies with severe eczema or an existing egg allergy, testing first is sensible. This is the exact question the LEAP study answered: introducing peanut early reduced peanut allergy by 81% in high-risk infants. We help families apply that evidence safely.

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Ready to find out what your child is reacting to?

Whether you're seeking answers about persistent symptoms or looking for expert care for your child, we're ready to help. Book a consultation with our specialists and take the first step towards understanding and managing your allergies effectively.
Speak to the Team
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Allergy Centre of Excellence (ACE)
10 Duchess Street
London W1G 9AB
The Portland Hospital 

215 Great Portland Street, 2nd floor
London W1W 5QT 

07493 280048 
/ 07765 977819
admin@londonallergy.com
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