Can a blood test confirm my child has a food allergy?

A specific IgE blood test measures sensitisation to particular allergens, which can suggest an allergic tendency. However, a blood test alone does not confirm a clinical allergy diagnosis.

How long does it take to receive allergy blood test results?

Turnaround times can vary. Private allergy blood testing in London often provides results within a few working days. NHS pathways may involve longer waiting periods.

At what age can children have an allergy blood test?

Allergy blood tests can generally be performed on children from a young age, including infants. The suitability of testing should be discussed with a healthcare professional.

Will a nursery accept private allergy test results?

Yes, most nurseries in London accept results from both NHS and private laboratories, provided the report is clearly formatted and issued by a recognised testing provider.

What happens if my child's allergy test results are negative but they still react to certain foods?

A negative specific IgE result means that IgE-mediated sensitisation was not detected for that allergen at the time of testing. Non-IgE-mediated allergies and food intolerances may not be detected through this type of blood test.

Do I need a GP referral for private allergy blood testing in London?

Many private allergy testing clinics in London, including our clinic, do not require a GP referral. You can typically book directly.

Can nursery allergy documentation be updated if my child's allergies change?

Yes, and it is recommended that you update your child's allergy documentation if new test results are obtained or if their allergy profile changes.

What is the difference between an allergy and a food intolerance?

An allergy involves an immune system response, often mediated by IgE antibodies, and can sometimes cause severe reactions. A food intolerance typically involves digestive difficulty and does not involve the immune system in the same way.

Where can I get allergy testing for my child in London?

Allergy blood testing is available through the NHS via GP referral or through private clinics in London.

Nurseries in London: Providing Proof of Allergy for Enrollment

What Does “Proof of Allergy for Nursery Enrollment” Mean?

Proof of allergy for nursery enrollment refers to formal documentation — typically a medical report or laboratory test result — that confirms a child has a specific allergy. London nurseries increasingly request this evidence as part of their admissions process to help safeguard children and establish appropriate care plans. This documentation may include specific IgE blood test results, a letter from a healthcare professional, or a structured allergy action plan.

For many parents across London, the nursery enrollment process can feel overwhelming, particularly when a child has known or suspected allergies. Nurseries have a duty of care to every child in their setting, and understanding what allergies a child may have is a fundamental part of fulfilling that responsibility. Providing clear, reliable proof of allergy for nursery enrollment helps ensure your child's safety and gives nursery staff the information they need to respond appropriately.

This guide explains why nurseries request allergy documentation, the types of evidence typically accepted, how allergy blood testing works, and how you can obtain the reports you need in London.

Why Do London Nurseries Request Allergy Documentation?

Early years settings across London operate under strict Ofsted and local authority guidelines. These frameworks require nurseries to manage health risks, including allergic reactions, with documented care plans. When a parent reports that a child has an allergy, nurseries are expected to:

Request supporting evidence such as a test result or healthcare professional letter
Develop an individual care plan based on documented allergies
Train staff on recognising symptoms and responding to allergic reactions
Communicate dietary requirements to kitchen and catering teams
Store emergency medication (such as antihistamines or adrenaline auto-injectors prescribed by a healthcare professional)

Without formal documentation, nurseries may find it difficult to implement the specific adjustments a child needs. This is why many London nurseries now include allergy proof as a standard part of their enrollment paperwork.

Practical Insight: Starting the process of gathering allergy documentation well before your child's nursery start date can help avoid delays in enrollment and ensure a smoother transition.

Types of Allergy Evidence Accepted by Nurseries

Not all nurseries have identical requirements, but the following types of documentation are commonly accepted across London early years settings:

Type of Evidence	What It Includes	Typically Accepted?
Specific IgE blood test report	Laboratory results showing IgE levels for specific allergens	Yes — widely accepted
Skin prick test results	Report from a clinical setting documenting skin prick test outcomes	Yes — usually accepted
GP or healthcare professional letter	Written confirmation of diagnosed allergy	Yes — commonly requested
Allergy action plan	Structured plan detailing triggers, symptoms, and emergency steps	Yes — often required alongside test results
Parent self-report only	Verbal or written statement from parent without clinical evidence	Sometimes — but many nurseries now require formal documentation

Many nurseries prefer laboratory-based evidence, such as specific IgE blood test results, because these provide a clear, objective record of sensitisation to particular allergens.

Practical Insight: It may be helpful to contact your chosen nursery directly to ask which forms of allergy documentation they accept, so you can prepare the correct evidence in advance.

Understanding Allergy Blood Tests: What Do They Measure?

Allergy blood tests, sometimes known as specific IgE tests, measure the level of immunoglobulin E (IgE) antibodies in the blood that correspond to particular allergens. When the immune system identifies a substance as a potential threat, it can produce IgE antibodies specific to that substance. Elevated levels of specific IgE may suggest sensitisation to an allergen, which can support further assessment by a healthcare professional.

Common Allergens Tested in Children

For nursery-age children, the most frequently requested allergen panels typically include:

Cow's milk (casein, whey proteins)
Hen's egg (egg white, egg yolk)
Peanut
Tree nuts (such as cashew, walnut, hazelnut)
Wheat (parents who have switched to oat milk as a dairy alternative should note that oat-based products can sometimes trigger reactions of their own)
Soya
Fish and shellfish
Sesame (tree nut and sesame allergies can be triggered by unexpected products — including viral food trends like Dubai chocolate bars)

These align with the 14 major allergens recognised under UK food labelling regulations, which nurseries are also required to manage within their catering provisions.

What Do the Results Mean?

Specific IgE blood test results are typically reported as a numerical value measured in kU/L (kilounits per litre). Results are generally categorised as:

< 0.35 kU/L — Below detection level; sensitisation unlikely based on this test
0.35–0.70 kU/L — Low level; may suggest mild sensitisation
0.71–3.50 kU/L — Moderate level; can indicate sensitisation
3.51–17.50 kU/L — High level; sometimes highlights significant sensitisation
> 17.50 kU/L — Very high level; may indicate strong sensitisation

It is important to understand that a positive IgE result indicates sensitisation, which does not automatically confirm a clinical allergy. The results should be interpreted alongside the child's clinical history by an appropriate healthcare professional. A blood test alone does not constitute a diagnosis, but it provides valuable evidence that supports the broader assessment process. For a more detailed understanding of which specific proteins your child is sensitised to, molecular diagnostics (component-resolved testing) can sometimes provide additional clarity that supports more targeted dietary guidance.

Practical Insight: When sharing test results with a nursery, it can be helpful to include a brief summary from a healthcare professional explaining which allergens were identified and what precautions are recommended.

If you would like to learn more about how IgE testing works and what result values mean, our guide on how to read your lab report provides further detail.

Who Should Consider Allergy Testing Before Nursery Enrollment?

Allergy testing before nursery enrollment may be particularly relevant for children who:

Have experienced symptoms such as hives, swelling, digestive discomfort, or skin reactions after exposure to certain foods (in some cases, persistent skin irritation in young children can be mistaken for sensory processing difficulties rather than an undiagnosed allergy)
Have a family history of allergic conditions, including eczema, asthma, or food allergy (children with atopic tendencies may also react to environmental allergens — for example, if your child attends horse riding lessons in London, equine allergens are another potential trigger worth considering)
Have been on restricted diets due to suspected but unconfirmed allergies
Are transitioning from home care or a childminder where allergen management was handled informally
Are enrolling in a nursery that specifically requires documented allergy evidence

Testing can also be helpful for parents who wish to clarify whether a suspected reaction was truly allergy-related, providing a clearer picture before the child enters a group care environment.

Practical Insight: If your child has experienced a reaction to a food but has not yet had formal testing, obtaining a blood test report may help both you and the nursery team manage the situation with greater confidence.

How Often Should Allergy Testing Be Repeated?

Childhood allergies can change over time. Some children may outgrow certain food allergies — particularly to milk and egg — while others may develop new sensitivities. For this reason, periodic retesting can be useful.

General guidance suggests:

Every 12–24 months for young children with known food allergies, depending on clinical advice
When new symptoms appear that may suggest a new or changed allergy profile
Before key transitions such as moving from nursery to primary school, when a new care plan may be needed

Any decision to retest should ideally be guided by advice from a healthcare professional who can assess whether retesting is appropriate based on the child's history. For more information about paediatric allergy testing, see our dedicated guide.

London Context: Navigating Nursery Allergy Policies

London's diverse nursery landscape means that allergy documentation requirements can vary between boroughs, nursery chains, and independent settings. Some key points for London-based parents:

Local authority nurseries often follow borough-specific guidance on allergy management, which may include mandatory documentation
Private and independent nurseries frequently set their own enrollment requirements, with many requesting formal test results
Childminder networks registered with Ofsted are also expected to manage allergies with documented plans

The NHS provides allergy testing through GP referrals, though waiting times can vary depending on local demand. Private allergy blood testing offers an alternative pathway for obtaining results, sometimes with shorter turnaround times. For children with complex or severe allergies, NHS specialist allergy clinics may offer the most appropriate level of assessment. Both NHS and private test results are generally accepted by nurseries, provided they include clear, professional reporting.

NHS vs Private Allergy Testing: A Comparison

Factor	NHS Pathway	Private Testing (e.g., Allergy Clinic UK)
Access	Via GP referral to allergy clinic	Direct booking; no referral needed
Waiting time	Can vary by borough and local demand	Often shorter; availability may vary
Cost	Free at point of care	Fee applies — check the clinic website for current information
Report format	Clinical letter or hospital report	Laboratory report with detailed allergen breakdown
Accepted by nurseries	Yes	Yes

Practical Insight: If your child's nursery start date is approaching and you require allergy documentation, checking current availability at both NHS and private services in London can help you plan accordingly.

Preparing Your Child's Allergy Documentation Pack

When submitting allergy proof to a nursery, it can be helpful to prepare a complete documentation pack. This might include:

Laboratory test results — specific IgE blood test report clearly showing allergens tested and results
Healthcare professional letter — a summary from a GP or relevant professional confirming the allergy and any recommendations
Allergy action plan — a step-by-step document outlining what to do if the child is exposed to an allergen, including emergency medication details if prescribed
Emergency medication details — information about any prescribed medication, dosage, and storage requirements
Dietary guidance — a clear list of foods to avoid and safe alternatives

Having all documents ready in advance can support a more efficient enrollment process and help nursery staff feel well-equipped to care for your child.

Practical Insight: Keeping a digital copy of all allergy documentation is useful, as nurseries may request updated copies periodically or if your child transfers to a new setting.

Frequently Asked Questions

What proof of allergy do London nurseries typically require for enrollment?: Most London nurseries request formal documentation such as specific IgE blood test results, a letter from a healthcare professional, or a structured allergy action plan. Requirements can vary between settings, so it is advisable to check directly with your chosen nursery. Having proof of allergy for nursery enrollment prepared in advance can help streamline the admissions process.
Can a blood test confirm my child has a food allergy?: A specific IgE blood test measures sensitisation to particular allergens, which can suggest an allergic tendency. However, a blood test alone does not confirm a clinical allergy diagnosis. Results should be reviewed alongside the child's history by an appropriate healthcare professional to determine clinical significance.
How long does it take to receive allergy blood test results?: Turnaround times can vary depending on the testing provider. Private allergy blood testing in London often provides results within a few working days. NHS pathways may involve longer waiting periods depending on local service availability.
At what age can children have an allergy blood test?: Allergy blood tests can generally be performed on children from a young age, including infants. The suitability of testing for a particular child should be discussed with a healthcare professional who can advise based on the child's individual circumstances. For more detail, see our gentle guide to paediatric allergy testing.
Will a nursery accept private allergy test results?: Yes, most nurseries in London accept results from both NHS and private laboratories, provided the report is clearly formatted and issued by a recognised testing provider. If unsure, you may wish to share a sample report format with the nursery before booking your test.
What happens if my child's allergy test results are negative but they still react to certain foods?: A negative specific IgE result means that IgE-mediated sensitisation was not detected for that allergen at the time of testing. However, non-IgE-mediated allergies and food intolerances exist and may not be detected through this type of blood test. Further assessment through appropriate healthcare services may be recommended.
Do I need a GP referral for private allergy blood testing in London?: Many private allergy testing clinics in London, including our clinic, do not require a GP referral. You can typically book directly. Visit our testing page for further information about the booking process.
Can nursery allergy documentation be updated if my child's allergies change?: Yes, and it is recommended that you update your child's allergy documentation if new test results are obtained or if their allergy profile changes. Nurseries should be informed promptly of any changes to ensure care plans remain accurate.
What is the difference between an allergy and a food intolerance?: An allergy involves an immune system response, often mediated by IgE antibodies, and can sometimes cause severe reactions. A food intolerance typically involves digestive difficulty and does not involve the immune system in the same way. Blood tests measuring specific IgE are designed to detect allergic sensitisation rather than food intolerance. For more information, see our article on understanding total IgE vs specific IgE.
Where can I get allergy testing for my child in London?: Allergy blood testing is available through the NHS via GP referral or through private clinics in London. Our clinic offers children's allergy panel testing with professional laboratory reporting suitable for nursery enrollment documentation.