Accurate IgE Antibody Blood Testing in London – Food & Allergy Diagnostics You Can Trust

Need Allergy Testing? Book a Private IgE Antibody Blood Test in London or take at home.

Whether you're struggling with unexplained symptoms, food reactions or persistent skin issues, our IgE antibody blood test in London offers a precise way to diagnose allergies. This test is designed to detect IgE antibodies—immune system markers that play a key role in allergic responses.

At London Allergy Consultants, we provide consultant-led testing, including ImmunoCAP (previously known as RAST), ALEX, and ISAC microchip blood tests. These methods help detect both broad and component-specific allergic reactions for food, environmental, and inhalant allergens.

Same-Week Appointments | Paediatric & Adult Testing | Home Testing Available | Self-pay and Insurance Welcome

★★★★★

“Dr du Toit is a fantastic specialist, my son and I both very much respect and value his expertise. We have seen many doctors over the years and Dr du Toit is one of those special doctors that can really make a difference in a person’s life.”

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What Is an IgE Antibody Blood Test?

An IgE antibody blood test measures the levels of allergen-specific IgE in your blood. These antibodies are produced in response to allergens such as pollen, foods, pet dander or insect venom. This type of test, when guided by a detailed clinical history, is useful for diagnosing IgE-mediated allergic reactions, particularly when skin prick testing is not possible or conclusive.

IgE testing is commonly used for:

  • Food allergy testing (milk, egg, peanut, shellfish, soy, wheat and more)

  • Aeroallergen screening (pollen, dust mite, animal dander, mould)

  • Drug allergies (penicillin, latex, chlorhexidine, gelatin)

  • Insect venom reactions (bee, wasp, fireant)

IgE testing is safe for all ages and does not require stopping antihistamines or other medications.

We can post out home testing kits anywhere in the UK. Blood is then collected by finger prick. The results can then be communicated via remote appointment.

Why Choose Us for a Skin Prick Test in London?

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    Same-Week Testing Appointments

    Results within days

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    GMC-Registered Allergy Consultants

    Clinical leadership in food and environmental allergy testing

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    Paediatric & Adult Services

    From infancy to adulthood

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    Advanced Testing Technology

    ImmunoCAP, ALEX, ISAC & more

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    Convenient Location

    Our clinic is conveniently located in London, with easy access to public transportation.

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ImmunoCAP (formerly RAST) Testing – The Trusted Standard

ImmunoCAP testing, previously referred to as RAST testing, is the current laboratory standard for IgE blood testing. It offers:

  • Quantitative results for specific IgE to hundreds of allergens

  • Consistent, lab-standardised results (unlike skin tests, which can vary)

  • Ideal for patients who are on antihistamines or have extensive eczema

  • We routinely use IgE component testing to provide the most accurate allergy diagnosis. This advanced testing method helps us identify specific allergen components, enabling us to better predict the severity of allergic reactions.

We use IgE tests for:

  • Food allergy testing (component testing is available for peanut, many tree nuts, shellfish, soya, milk, egg, sesame…)

  • Respiratory allergens (pollen, mould, dust mites)

  • Pet dander (cat, dog, horse, rabbit, farm animals…)

  • Latex and medication allergies (chlorhexidine, gelatine, Penicillins)

IgE testing (Immunocap, ALEX, ISAC) is especially useful in complex allergy cases where multiple systems, such as allergic eczema, asthma, and food allergy, may be affected.

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ALEX and ISAC Tests – Component-Resolved Allergy Diagnostics

For patients with complex or unclear allergic reactions, we offer cutting-edge microarray testing using the ALEX and ISAC platforms.

ALEX (Allergy Explorer Test)

  • Tests for 300+ allergens

  • One small blood sample

  • Includes both whole allergen extracts and molecular components

  • Helpful in identifying cross-reactivity (e.g. pollen-food syndrome)

  • Helps assess risk of severe reaction vs. mild/localised symptoms

ISAC (Immuno Solid-Phase Allergen Chip)

  • High-sensitivity panel for 112 allergen components

  • One small blood sample

  • Ideal for identifying hidden or overlapping allergies

  • Provides detailed molecular diagnosis in patients with multiple sensitivities

These tools help us provide a clearer picture of how your immune system responds, supporting better decisions on avoidance, medication or immunotherapy.

How It Works: From Consultation to Diagnosis

We follow a thorough process to ensure accuracy and clarity:

1. Initial Consultation

One of our consultants will take a full clinical history to understand your symptoms, background, and suspected triggers. If you prefer, we can do this as a remote consultation, by telephone or Zoom.

2. Test Selection

Based on your symptoms, we may recommend ImmunoCAP, ALEX, ISAC or a combination.

3. Blood Sample Collection

A simple blood draw is taken by phlebotomy and sent to a specialist laboratory.

Alternatively, the sample can be returned to our laboratory after home-based finger-prick blood collection (applies to ALEX or ISAC testing, where only a tiny blood volume is needed).

4. Results Review

Your consultant will review the results with you in detail and explain what they mean, either face-to-face or remotely.

5. Management Plan

You’ll receive tailored advice on allergen avoidance, treatment e.g. OIT, SLIT, Medicines, and long-term care.

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Who Should Consider an IgE Antibody Blood Test?

You may benefit from IgE blood testing if you:

  • Have complex and multiple allergic diseases, e.g. food allergy, oral allergy syndrome, hayfever, pet and dust mite-induced eczema

  • Cannot stop antihistamines before skin testing.

  • Have dermatological conditions like extensive eczema

  • Unable to travel to one of our clinics and would prefer remote or home-based testing.

  • Are seeking a second opinion after a skin prick test

  • Want detailed allergy profiling, offered through component resolved diagnostic tests to help understand primary vs secondary food allergies (aka oral allergy syndrome)

We test infants, children, teenagers and adults.

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Understanding Your Results

Your consultant will review all test results in detail with you. We’ll explain what your IgE levels mean and provide a clear interpretation based on your medical history.

Allergy blood test results can:

  • Help confirm allergy vs. tolerance

  • Differentiate between troublesome primary and milder secondary food allergies (Oral Allergy Syndrome)

  • Help to understand positive SPT results that may not be clinically relevant, e.g., positive tests for Prawn (Shrimp) that arise due to cross-reactivity with Dust Mite proteins instead of primary shrimp (shellfish) allergy.

  • Predict the likelihood and severity of future reactions

  • Monitor whether allergies are resolving over time

  • Guide immunotherapy decisions, e.g. when to start, chance of treatment success

No test can 100% predict the severity of a future reaction, but component-resolved diagnostics (ALEX and ISAC) can provide important insight into reaction risk and cross-sensitivities.

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Choosing Reliable Allergy Testing

When it comes to identifying allergies, accuracy and clinical relevance are essential. It's important to understand the difference between medically validated tests and those that are not supported by evidence.

There are several tests widely available online and on the high street—such as IgG or IgG4 antibody testing, cytotoxic testing, kinesiology, Vega testing, and iridology—that are not recommended by clinical allergy guidelines. These methods may result in confusing or misleading interpretations and can lead to unnecessary dietary restrictions or anxiety.

At London Allergy Consultants, we follow recognised clinical protocols that start with a detailed history taken by a qualified healthcare professional. Our diagnostic pathway includes validated tools like Specific IgE blood testing (ImmunoCAP), ALEX and ISAC testing, and, when appropriate, skin prick tests or oral food challenges.

If you’re unsure which type of allergy testing is right for you, our team will guide you based on your symptoms, history and testing goals.

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Meet Our Allergy Testing Specialists

Our team includes experienced consultants with years of clinical expertise in diagnosing and managing allergies in both adults and children. Each of our doctors specialises in different areas of allergy care to provide the most accurate and thorough service possible.

✔ Led by Professor George du Toit – world-leading paediatric allergy specialist
✔ Dr Ru-Xin Foong, experienced in state-of-the-art allergen diagnosis and treatments.
✔ Evidence-based, research-backed treatments, with close regulatory oversight
✔ Personalised, patient-centred approach in London and Surrey Clinics.
✔ Child-friendly, safe, and supportive environment

We are proud to provide leading care for those seeking a trusted skin prick test in London.

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Our Locations – Accessible Clinics Across London & Surrey

We provide expert allergy care at multiple locations, ensuring convenient access to specialized treatment for food and airborne allergies.

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The Portland Hospital – Marylebone

📍 Address: 205-209 Great Portland Street, London, W1W 5AH

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ENT4Kids – Wimpole Street, London

📍 Address: 61 Wimpole Street, London,
W1G 8AH

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The Allergy Centre Of
Excellence

📍 Address: 10 Duchess Str, Marylebone,
W1B 9AB

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Surrey – New Malden Diagnostic Centre

📍 Address: 171 Clarence Avenue, New Malden, KT3 3TX

 Frequently Asked Questions

  • The cost of an IgE test can vary depending on the type of panel you need. At private clinics in London, prices usually range from £80 to £250. This may include the consultation, sample collection and lab analysis. We’ll confirm all costs before your appointment.

  • Yes, in some cases. If your GP suspects an allergy, they may arrange a referral for allergy testing. This could include a specific IgE blood test—sometimes still referred to as a RAST test. Most NHS allergy testing takes place in outpatient clinics, and availability may depend on referral guidelines.

  • IgE testing is a well-validated method used globally for allergy diagnosis. ImmunoCAP, ALEX and ISAC tests are considered clinically reliable, especially when paired with a full clinical history. However, no test is perfect—interpretation by a specialist is key.

  • While there is no single threshold for all patients, elevated IgE levels (typically over 100 kU/L) may indicate sensitisation to allergens. Your consultant will assess your IgE results in the context of your symptoms and medical history.

  • Private allergy testing provides rapid access, a wide choice of testing platforms (like ALEX and ImmunoCAP), and consultant-led interpretation. For many people, this means faster diagnosis, personalised advice and a clear management plan.

  • No, fasting is not required. You can eat and drink normally before your appointment. Medications like antihistamines do not affect blood test results, which is another reason IgE testing is often preferred in certain situations.

  • IgE antibodies can remain in the bloodstream for up to two years. Their levels may fluctuate depending on exposure to allergens and the presence of allergy symptoms.

  • Some pharmacies offer rapid blood test kits, but these typically cover a small number of allergens and are not always interpreted by medical professionals. For accurate and personalised allergy testing in London, a full clinical assessment and lab-based testing are recommended.

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Book Your IgE Antibody Blood Test in London

Get tested by experienced allergy consultants using the most advanced diagnostics available. Whether you're investigating food reactions, seasonal symptoms or chronic skin issues, our team is here to help.