What is the Soybean IgE test?

The Soybean IgE test is a blood test that measures immunoglobulin E (IgE) antibodies specific to proteins found in soybeans. IgE antibodies are involved in immediate allergic reactions, which can occur minutes to hours after exposure.

This test helps distinguish a true soy allergy from non-allergic food intolerance. It is commonly used alongside clinical history and, when appropriate, other allergy investigations.

Why do I need a Soybean IgE test?

Soy is a common food ingredient found in many processed foods, sauces, and plant-based products. Reactions can range from mild symptoms to severe systemic responses, including anaphylaxis.

Testing is useful when symptoms occur after consuming soy or soy-containing products, or when soy is suspected but the trigger is unclear.

You may benefit from this test if you experience:

• Hives, itching, or eczema flares after eating soy
• Lip, tongue, or throat swelling
• Abdominal pain, nausea, vomiting, or diarrhoea
• Wheezing, cough, or breathing difficulty
• Symptoms after eating tofu, soy milk, soy sauce, or processed foods
• Known food allergy with suspected soy cross-reactivity

Benefits of the Soybean IgE test

1. Identifies IgE-mediated soy allergy
   Confirms allergic sensitisation to soy proteins.
2. Differentiates allergy from intolerance
   Helps avoid unnecessary dietary restriction.
3. Supports safer dietary planning
   Guides avoidance and food-label vigilance.
4. Assesses allergy risk
   Relevant for individuals with systemic reactions.
5. Simple blood test
   No food challenge required.
6. Suitable for children and adults
   Commonly used in paediatric and adult allergy assessment.
7. Supports specialist referral
   Aids decisions about allergy clinic review.
8. Improves long-term allergy management
   Supports education and emergency planning.

Step-by-step – How we offer this test

Option 1: Clinic-based blood test (UK-wide)

• Choose your nearest UK clinic
• Attend your appointment
• A clinician draws a blood sample
• Sample analysed for soybean-specific IgE

Option 2: Home or hotel visit (+£60, UK-wide)

• A qualified phlebotomist visits your location
• Blood sample taken at home or in your hotel
• No travel required
• Same laboratory processing and reporting

Your results explained

Low or negative Soybean IgE

Low or undetectable IgE suggests no evidence of IgE-mediated soy allergy.

Typical UK interpretation:

• < 0.35 kU/L

Symptoms may still be due to intolerance or non-IgE reactions.

Borderline or low-positive Soybean IgE

Borderline levels may indicate sensitisation without clear clinical allergy.

Typical UK interpretation:

• 0.35 – 0.7 kU/L

Interpret alongside symptoms and exposure history.

High Soybean IgE

High IgE levels indicate allergic sensitisation and increased likelihood of clinical reactions.

Typical UK interpretation:

• > 0.7 kU/L

IgE level does not reliably predict reaction severity.