Can an allergy test tell me whether I have eczema or psoriasis?

An allergy test alone cannot diagnose eczema or psoriasis. However, measuring specific IgE antibodies and total IgE levels can sometimes indicate whether allergic sensitisation may be contributing to your skin symptoms. Eczema is frequently associated with elevated IgE, whereas psoriasis typically involves different immune pathways. Sharing your results with an appropriate healthcare professional can help clarify the picture.

What type of allergy test is most useful for skin conditions?

A specific IgE blood test is often the most informative for exploring potential allergic contributors to skin symptoms. This measures your immune response to individual allergens such as foods, dust mites, moulds, and animal dander. Total IgE testing can also provide useful context regarding your overall allergic tendency.

Is an allergy blood test the same as a skin prick test?

No. A blood test measures IgE antibodies in your blood sample, while a skin prick test involves introducing small amounts of allergen to the skin surface. Both approaches assess allergic sensitisation but use different methods. Blood tests can be particularly convenient as they are unaffected by antihistamine use and can test multiple allergens simultaneously.

How long does it take to get allergy test results?

At most private clinics, allergy blood test results are typically available within a few working days, depending on the specific panel requested. Our clinic provides clear, structured reports that you can then share with your healthcare provider for further interpretation and guidance.

Can food allergies cause eczema flare-ups?

In some individuals — particularly young children — food allergens such as cow's milk, eggs, wheat, soya, and nuts may contribute to eczema flare-ups. Specific IgE testing can help identify whether sensitisation to these foods is present, though sensitisation does not always equate to clinical allergy. Dietary changes should only be made under appropriate healthcare guidance.

Should I get an allergy test if I think I have psoriasis?

While psoriasis is not typically driven by classical allergy, some individuals with psoriasis may also have concurrent allergic sensitivities. An allergy test can help rule allergic triggers in or out, and the information may be useful when discussing your symptoms with a healthcare professional.

Can stress trigger both eczema and psoriasis?

Stress is widely recognised as a potential trigger for flare-ups in both conditions. While an allergy test does not measure stress, it can help determine whether other factors — such as environmental or food allergens — may also be contributing to symptom patterns alongside stress.

Is allergy testing suitable for children with skin problems?

Yes. Blood-based allergy testing is generally suitable for children and can be particularly valuable given that childhood eczema is frequently associated with food and environmental allergies. Testing can help identify potential sensitisations early, supporting more informed discussions with paediatric healthcare providers.

How much does an allergy test cost in London?

Pricing varies depending on the panel selected and the number of allergens tested. For current pricing and available allergy screening packages, please visit our clinic website for the most up-to-date information.

Can I request allergy testing without a GP referral?

Yes. At our London clinic, you can book allergy blood testing directly without a GP referral. The process is straightforward, and you'll receive a clear report that you can share with your GP or any other relevant healthcare professional.

Eczema vs. Psoriasis: How an Allergy Test Clears the Confusion

Living with persistent skin irritation can be both physically uncomfortable and emotionally draining — particularly when you're unsure whether you're dealing with eczema, psoriasis, or an underlying allergic response. For many people across London and the wider UK, an allergy test can be a valuable first step in understanding what may be contributing to chronic skin symptoms. Rather than guessing or relying on generalised advice, testing can provide structured, personalised data that helps you and your healthcare provider make more informed decisions.

In this guide, we explore the key differences between eczema and psoriasis, examine how allergy blood testing may help clarify the picture, and explain what your results could mean for your long-term wellbeing.

What Is the Difference Between Eczema and Psoriasis?

Eczema (atopic dermatitis) is a chronic inflammatory skin condition often linked to immune hypersensitivity and allergic responses. Psoriasis is an autoimmune condition where the skin cell lifecycle accelerates, leading to thick, scaly patches. While both conditions cause redness, itching, and discomfort, their underlying mechanisms, triggers, and associated biomarkers differ significantly — and an allergy test can sometimes help distinguish between them.

Both conditions affect millions of people in the UK. According to the National Eczema Society, around 1 in 5 children and 1 in 10 adults in the UK live with eczema. Psoriasis affects approximately 1.8 million people across England and Wales. Despite their prevalence, many individuals go years without a clear understanding of which condition they may have — or whether allergic triggers are playing a role.

Practical Insight: If you've experienced recurring skin flare-ups that haven't responded to general skincare changes, exploring whether allergic sensitisation may be involved can sometimes offer useful clarity.

Eczema vs. Psoriasis: A Side-by-Side Comparison

Feature	Eczema (Atopic Dermatitis)	Psoriasis
Appearance	Red, inflamed, sometimes weeping patches	Thick, silvery-white scaly plaques
Common Areas	Inner elbows, behind knees, face, hands	Outer elbows, knees, scalp, lower back
Itch Severity	Often intense, may disrupt sleep	Can itch, but may also burn or sting
Age of Onset	Commonly begins in childhood	Often appears between ages 15–35
Allergic Link	Frequently associated with allergies (food, environmental)	Not typically allergy-driven
Immune Mechanism	Hypersensitivity / IgE-mediated responses	Autoimmune — accelerated skin cell turnover
Family History	Often linked to asthma, hay fever, food allergies	May run in families, linked to autoimmune conditions
Relevant Blood Markers	Total IgE, specific IgE panels	CRP, ESR (inflammatory markers)

This comparison highlights a critical distinction: eczema is frequently associated with allergic sensitisation, whereas psoriasis is driven by a different immune pathway. This is precisely where allergy blood testing can sometimes help clarify what may be happening beneath the surface.

How Can an Allergy Test Help with Skin Conditions?

When skin symptoms persist, many people wonder whether something they're eating, breathing, or coming into contact with could be contributing to their flare-ups. An allergy blood test measures specific IgE antibodies — proteins the immune system produces in response to particular allergens. Elevated IgE levels to certain foods or environmental substances may suggest allergic sensitisation, which is more commonly associated with eczema than psoriasis.

Key Biomarkers That May Be Relevant

Total IgE (Immunoglobulin E): A general marker of allergic tendency. Elevated total IgE levels can sometimes be observed in individuals with atopic eczema, though raised levels alone do not confirm a diagnosis.
Specific IgE Panels: These measure immune responses to individual allergens — such as house dust mites, pet dander, grass pollen, milk, eggs, wheat, or nuts. Results may highlight sensitisation patterns that could be relevant to skin symptoms.
CRP (C-Reactive Protein): A general inflammatory marker. While not specific to either condition, it can sometimes indicate the presence of systemic inflammation.
Full Blood Count (FBC): Eosinophil counts within a full blood count may sometimes be elevated in allergic conditions, including atopic eczema.

Practical Insight: Allergy blood testing does not diagnose eczema or psoriasis directly. However, it can provide valuable supporting information — particularly when results are shared with an appropriate healthcare professional who can interpret them alongside your clinical history.

If you're interested in understanding more about what blood tests can reveal, our guide on blood test services provides a helpful overview of available screening options.

Who Should Consider Allergy Testing for Skin Symptoms?

Not everyone with a rash or dry skin patch needs an allergy test. However, testing may be particularly worth considering if you:

Have recurring skin flare-ups that don't respond to basic moisturising or skincare routines
Notice that symptoms seem to worsen after eating certain foods or during specific seasons
Have a personal or family history of asthma, hay fever, or food allergies (the "atopic triad")
Experience skin irritation alongside nasal congestion, itchy eyes, or digestive discomfort
Want to explore whether environmental allergens such as dust mites or pet dander may be contributing factors
Are unsure whether your symptoms align more closely with eczema or psoriasis patterns

For London residents, access to private allergy testing can sometimes offer a more convenient route to gathering this information, particularly when NHS waiting times for specialist referrals may be lengthy.

Practical Insight: If you've been managing skin symptoms for months — or even years — without clear answers, allergy screening can sometimes offer a structured starting point for further investigation with your healthcare provider.

What Do Allergy Test Results Mean?

Understanding your allergy test results is an important part of the process. Here's what different outcomes may suggest:

Elevated Specific IgE to Certain Allergens

This may indicate sensitisation to a particular substance. It's important to note that sensitisation does not always mean clinical allergy — some people produce IgE antibodies without experiencing symptoms. However, when elevated IgE results align with a pattern of skin flare-ups, this information can be extremely valuable for further clinical assessment.

Elevated Total IgE

A raised total IgE level can sometimes be associated with atopic conditions, including eczema. It may suggest a general allergic tendency, though it is not specific to any single allergen or condition.

Normal IgE Levels

If IgE levels are within the expected range, this may suggest that classical allergic sensitisation is less likely to be the primary driver of your skin symptoms. In such cases, exploring other possible contributing factors — such as autoimmune markers or skin barrier dysfunction — may be the next appropriate step with a healthcare professional.

Raised Inflammatory Markers

Elevated CRP or eosinophil counts may suggest ongoing inflammation, which can be associated with both eczema and psoriasis. These markers provide context rather than a specific answer.

It's essential to remember that test results should always be reviewed alongside your full clinical picture. Our clinic provides testing and reporting — we recommend sharing your results with an appropriate healthcare professional for personalised interpretation.

For more information about how allergy testing works, you may find our guide on blood tests vs skin prick testing helpful.

How Often Should You Consider Allergy Testing?

The frequency of allergy testing depends on individual circumstances. As a general guide:

Initial baseline testing can be valuable if you've never been tested and are experiencing unexplained skin symptoms
Annual or periodic re-testing may be appropriate if your symptoms change, new triggers are suspected, or you wish to monitor previously identified sensitivities
Follow-up testing after lifestyle or dietary modifications can sometimes help assess whether sensitisation patterns have shifted over time

For children with eczema, allergy profiles can change as the immune system matures — so periodic review may be particularly relevant.

Practical Insight: There is no single "right" frequency for everyone. If you're unsure whether re-testing would be appropriate, speaking with a healthcare professional can help guide your decision.

The London Context: Accessing Allergy Testing Privately

Living in London presents unique environmental considerations that can be relevant to skin health. High levels of air pollution, exposure to a wide range of indoor allergens in densely populated housing, and the diversity of dietary patterns across the capital all contribute to a complex picture when it comes to allergic skin conditions.

Many Londoners choose private allergy testing to:

Avoid lengthy NHS waiting times for dermatology or allergy specialist referrals
Gain faster access to structured blood test data
Take a proactive approach to understanding their own health markers

Private testing offers a convenient, structured way to gather data — while the NHS remains the appropriate route for ongoing clinical management, diagnosis, and treatment. The two approaches can work effectively alongside each other.

If you'd like to explore what's available, our health screening options outline the testing panels we currently offer at our London clinic.

Eczema, Psoriasis, and the Wider Allergy Connection

It's worth noting that eczema and allergies frequently coexist as part of what's sometimes called the atopic march — a progression from eczema in early childhood to food allergies, hay fever, and asthma later in life. Understanding this connection through blood testing can sometimes provide a broader picture of immune function.

Psoriasis, by contrast, is less commonly associated with classical IgE-mediated allergy. However, individuals with psoriasis may still have concurrent allergic sensitivities, and testing can help separate these overlapping patterns.

For those interested in broader immune health screening, our comprehensive health check options may offer additional relevant markers beyond allergy-specific panels.

Practical Insight: Skin conditions rarely exist in isolation. Understanding whether allergic sensitisation is part of your picture can sometimes help healthcare professionals tailor their advice more effectively.

Frequently Asked Questions

Can an allergy test tell me whether I have eczema or psoriasis?: An allergy test alone cannot diagnose eczema or psoriasis. However, measuring specific IgE antibodies and total IgE levels can sometimes indicate whether allergic sensitisation may be contributing to your skin symptoms. Eczema is frequently associated with elevated IgE, whereas psoriasis typically involves different immune pathways. Sharing your results with an appropriate healthcare professional can help clarify the picture.
What type of allergy test is most useful for skin conditions?: A specific IgE blood test is often the most informative for exploring potential allergic contributors to skin symptoms. This measures your immune response to individual allergens such as foods, dust mites, moulds, and animal dander. Total IgE testing can also provide useful context regarding your overall allergic tendency.
Is an allergy blood test the same as a skin prick test?: No. A blood test measures IgE antibodies in your blood sample, while a skin prick test involves introducing small amounts of allergen to the skin surface. Both approaches assess allergic sensitisation but use different methods. Blood tests can be particularly convenient as they are unaffected by antihistamine use and can test multiple allergens simultaneously.
How long does it take to get allergy test results?: At most private clinics, allergy blood test results are typically available within a few working days, depending on the specific panel requested. Our clinic provides clear, structured reports that you can then share with your healthcare provider for further interpretation and guidance.
Can food allergies cause eczema flare-ups?: In some individuals — particularly young children — food allergens such as cow's milk, eggs, wheat, soya, and nuts may contribute to eczema flare-ups. Specific IgE testing can help identify whether sensitisation to these foods is present, though sensitisation does not always equate to clinical allergy. Dietary changes should only be made under appropriate healthcare guidance.
Should I get an allergy test if I think I have psoriasis?: While psoriasis is not typically driven by classical allergy, some individuals with psoriasis may also have concurrent allergic sensitivities. An allergy test can help rule allergic triggers in or out, and the information may be useful when discussing your symptoms with a healthcare professional.
Can stress trigger both eczema and psoriasis?: Stress is widely recognised as a potential trigger for flare-ups in both conditions. While an allergy test does not measure stress, it can help determine whether other factors — such as environmental or food allergens — may also be contributing to symptom patterns alongside stress.
Is allergy testing suitable for children with skin problems?: Yes. Blood-based allergy testing is generally suitable for children and can be particularly valuable given that childhood eczema is frequently associated with food and environmental allergies. Testing can help identify potential sensitisations early, supporting more informed discussions with paediatric healthcare providers.
How much does an allergy test cost in London?: Pricing varies depending on the panel selected and the number of allergens tested. For current pricing and available allergy screening packages, please visit our clinic website for the most up-to-date information.
Can I request allergy testing without a GP referral?: Yes. At our London clinic, you can book allergy blood testing directly without a GP referral. The process is straightforward, and you'll receive a clear report that you can share with your GP or any other relevant healthcare professional.

Taking a Proactive Step Towards Clarity

Understanding your own health markers can be a helpful step — particularly when persistent skin symptoms have left you uncertain about what's happening and why. Whether you're exploring the possibility of allergic triggers, seeking to distinguish between eczema and psoriasis patterns, or simply want a clearer picture of your immune health, allergy blood testing can offer a structured, informative starting point.

At our London clinic, we provide professional allergy testing and clear, detailed reporting to support your health journey. We encourage you to explore our available testing options and take a proactive step towards better understanding your wellbeing — at a time and pace that feels right for you.