Allergy testing

Allergy testing involves observing your reaction to various substances to identify which substance or substances trigger your symptoms. This then allows your consultant to create a tailor-made treatment plan to help you manage your allergy.

There are several different types of allergy testing, including:

• Skin prick test
• Intradermal skin test
• Blood tests
• Skin patch test
• Provocation test

Call or book online today to arrange a consultation to discuss private allergy testing with a consultant of your choice at Circle Health Group.

This page explains what allergy testing is, why you may need to have allergy testing and what happens during the procedure.

The cost of this procedure depends on your individual circumstances. At the time of your appointment your consultant will discuss all options with you and ensure all your questions are answered.

Our fixed-price packages include the cost of your surgery and all appropriate aftercare appointments. However, any pre-surgery diagnostic tests and your consultant's outpatient appointment consultation fee are charged separately.

Our flexible payment options help you spread the cost of your payment across a time period that suits you.

Your consultant may recommend allergy testing if you have a severe allergy, or if it isn't clear what you are allergic to. Allergy testing may also be performed if you have atopic asthma, to identify substances that trigger your symptoms. In some cases, a type of allergy test called a provocation test may be recommended to see how severe your allergic reaction is under controlled conditions.

At your first consultation, you will be seen by a doctor specialising in allergies and allergy treatment. This may be a consultant dermatologist, Ear, Nose and Throat (ENT) surgeon, or an allergist.

Your consultant will ask you about your symptoms and perform a physical examination. They will also take a detailed allergy-focused medical history which may include questions about:

• What you suspect the allergen is
• Whether you have a history of atopic disease such as asthma, eczema, or allergic rhinitis (hay fever)
• Whether you have a close relative (parent or sibling) with a history of atopic disease or food allergy
• Any cultural and religious factors that affect which foods you eat
• Details of any foods you avoid and why
• Who has concerns and suspects a possible food allergy
• Your age when symptoms first started
• How quickly symptoms occur after exposure to the suspected allergen
• What symptoms you experience, how long they last and how severe they are
• How often you experience an allergic reaction
• Where your allergic reaction typically occurs (for example, at school or home)
• Whether symptoms occur every time you are exposed to the suspected allergen
• How much of the allergen you need to be exposed to before experiencing a reaction
• Any previous treatments you have tried and how well they worked
• Any response to eliminating and reintroducing foods
• If the patient is a child, their dietary history, whether they were breastfed or formula-fed, the age of weaning, and details of the mother's diet if the child is currently being breastfed

How is a diagnosis made?

Your consultant will make a diagnosis based on the results of your allergy tests.

Why is this first consultation so important?

At Circle Health Group, your first appointment is important as it's where you will meet your consultant, the doctor responsible for your care. Your consultant will spend time getting to know you, ask you about your symptoms, how they impact your life and any treatments you have tried.

Your first consultation is also an opportunity for you to ask your consultant any questions you may have. It is important to us that you are as well-informed and comfortable as possible during your time with us, so please discuss any questions or concerns you may have during your consultation.

At the end of your appointment, your consultant will discuss possible treatment options with you and decide on the best option based on your symptoms, test results and diagnosis.

There are a few things you need to do to prepare for your allergy testing to ensure your results are as accurate as possible. Instructions will be in your appointment letter. Please follow the instructions carefully and call the hospital if you have any questions.

• Before your appointment, tell your consultant about any medications, including over-the-counter medicines and supplements you are taking. Your consultant may advise you to stop taking certain medications such as antihistamines (including antihistamine nasal sprays), beta-blockers, tricyclic anti-depressants, and some types of antacids for a few days before your allergy testing appointment. Check with your consultant when you need to stop taking these medications.
• Take a shower before your allergy testing appointment to ensure your skin is clean. It's fine to wear deodorant, but avoid using body lotions, hairspray, cologne, or perfume on the day of your appointment
• You can continue to use steroid nasal sprays before your appointment
• You can eat and drink normally before your allergy testing. Bring a snack and a drink with you to your appointment if you would like to

There are various methods of allergy testing available. Your consultant will decide on the most appropriate type of allergy testing for you based on your symptoms, medical history, and diagnosis. 

Allergy tests include:

Skin prick test (scratch test)

A skin prick test is a safe, painless procedure that is usually the first test used to identify allergens. During the test, a tiny drop of allergen extract is placed on the skin and the skin is very lightly punctured using a shallow lancet. If you are allergic to the substance, specialised white blood cells called T-lymphocytes travel to the site of the allergen, creating a localised reaction (a red itchy wheal like a mosquito bite) after around 15 minutes. This will disappear after around 30 to 60 minutes. Skin prick testing can be used to identify several allergens at the same time. This test normally takes three to five minutes per allergen plus 15 to 20 minutes to see if a reaction occurs.

Intradermal skin test

If the skin prick test is inconclusive, your consultant may request an intradermal skin test. This test involves injecting a tiny amount of diluted allergen into the dermis layer of your skin and monitoring your reaction. It can be used to identify allergies such as insect stings, grass, and pollen. Intradermal skin testing takes around 30 to 40 minutes and positive results normally appear after 15 to 20 minutes.

Specific IgE blood test

This is a blood test to measure how much immunoglobulin E (IgE) your body produces when exposed to a certain allergen. Immunoglobulin E is a substance that your body produces during an allergic reaction and higher than normal levels indicate an allergy. A specific IgE blood test can be used to identify a range of allergies including food and drug allergies, hay fever, mould, and bee venom.

Though skin prick testing is normally preferable, a specific IgE blood test may be recommended where skin prick testing is not possible, such as for very young children, patients with certain skin problems or if there is a risk of anaphylaxis. A blood test only involves giving a sample of blood and therefore takes around ten minutes.

Patch Tests

This test is used to see if a skin reaction, such as eczema or contact dermatitis is caused by contact with a specific chemical or substance. The test involves taping small amounts of various allergens suspended in petroleum to the skin of your back for 48 hours. You should avoid bathing or activities that may cause excessive sweating while wearing the patches. After 48 hours, your consultant will remove the patches and check your skin for a reaction such as a rash. Applying the patches normally takes around three to five minutes per allergen.

Provocation Tests (allergen challenge test)

Provocation tests involve being exposed to your suspected allergen under carefully monitored conditions to establish if you are allergic or not, and how severe your reaction is. It is performed under medical supervision in an Outpatient or Day Case unit. During the test, you will be given gradually increasing amounts of the allergen and monitored for signs of an allergic reaction. There are three types of provocation tests:

• Oral provocation test - to check for food allergies
• Nasal provocation test - the suspected allergen (usually a type of pollen) is applied to the inside of the nose to check for hay fever symptoms
• Inhalation provocation test - is used to confirm or rule out the presence of atopic asthma in patients with respiratory disease

Provocation tests can take several hours, so it's a good idea to bring something such as a book to help pass the time. You will need to check with the staff before leaving the clinic during the test and must remain in the clinic for at least an hour after your last test.

After signing a consent form, a nurse will take some baseline observations including your pulse, blood pressure and peak flow reading (a test to measure the health of your lungs).

During the test, you will be exposed to increasing amounts of one substance at a time until you either develop an allergic response, or you have been exposed to a reasonable amount of the substance without a reaction. You can ask to stop the test at any time. If you have an allergic reaction, trained medical staff will be on hand to give you immediate treatment.

Recovering from allergy testing varies according to the type of allergy test you had and whether or not you experienced an allergic reaction during the test. Most people are fully recovered and able to resume normal activities within a few hours of allergy testing.

The aim of allergy testing is to provoke an allergic reaction. This is normally mild, but in rare cases may be severe. To minimise this risk, allergy tests are performed in a hospital environment under medical supervision so that any allergic reactions can be treated immediately should they occur. Most allergic reactions are mild and subside within a few hours.

Some possible risks and complications of allergy testing include:

• Mild itching, redness and swelling of the skin where the allergen was applied
• Mild allergy symptoms such as itchy, watery eyes and nasal congestion
• Small circular bumps (wheals) on the skin
• Feeling dizzy or lightheaded
• Anaphylaxis (rare)

You'll get the results of your skin prick and intradermal skin tests straight away. Patch tests can take several days, and the blood test results can take a week or longer.

There are two possible results of an allergy test:

• Negative - this result means you are not allergic to the substance tested
• Positive - a positive result means you are allergic to the substance tested. Even if your result is positive, it doesn't always mean you'll react to that allergen. False positive results (when the result is positive, but you don't have an allergy) are possible, especially from the blood test

What happens if I have an allergy?

If your allergy test results are positive, your consultant will work with you to create an individualised treatment plan best suited to your needs. This may include:

• Avoiding your allergy triggers
• Medication
• Immunotherapy (allergy shots)

At Circle Health Group, we have the experience and expertise to ensure the best possible care and outcome for our patients. As a patient with Circle Health Group, you can expect the highest standards of care including:

• Flexible appointment times and locations that are convenient for you
• The freedom to choose which hospital and consultant suit your needs
• Personalised, consultant-led treatment plans tailored to your individual needs
• Comfortable and safe private facilities maintained by expert multidisciplinary teams
• Private ensuite rooms as standard
• A range of delicious healthy meals
• Affordable, fixed-price packages with aftercare included
• Flexible payment options to help you spread the cost of your car

If you would like to see a consultant or learn more about allergy testing, book your appointment online today or call a member of our team directly on 0808 189 5499.

Content reviewed by Circle in-house team in April 2024. Next review due April 2027.

Allergies NHS

Allergy testing Anaphylaxis UK

Allergy testing  National Library of Medicine

Testing for allergies NHS Inform

Allergy-focused clinical history NICE