Private Intradermal Allergy Testing
Intradermal allergy testing is a specialist investigation that may help identify an allergy when initial tests have not provided a clear answer and an allergy is still suspected.
What is intradermal allergy testing?
Intradermal testing is a type of skin allergy test. It involves injecting a small amount of a diluted suspected allergen (drug or insect venom) just beneath the surface of your skin. The area is then examined for a response, such as a raised swelling, redness, or itching.
The test can be more sensitive than a skin prick test in certain clinical situations. However, it’s also less specific, which means a positive result does not necessarily confirm a clinically significant allergy. It might carry a slightly higher risk of triggering an allergic reaction, so it’s used selectively.
At Welbeck, intradermal testing is carried out by an allergy consultant as part of a drug or venom allergy assessment. Your consultant will consider whether intradermal testing is appropriate based on your symptoms, previous reactions, and the substance being investigated. Depending on your circumstances, skin prick testing or a blood test may be more suitable.
When is intradermal testing used?
Intradermal testing may be considered when investigating certain allergies, including:
drug allergies: selected suspected drug allergies, where skin testing is an appropriate part of the diagnostic assessment
insect venom allergies: such as suspected allergies to bee or wasp stings, particularly when initial tests have not provided a clear answer despite a convincing history
The suitability of intradermal testing depends on the suspected allergen, the type of reaction and the available evidence supporting the test. It is not appropriate for every suspected allergy, and your consultant may recommend a different investigation.
Paediatric intradermal testing
Welbeck offers paediatric allergy appointments for children aged 0 and above. However, intradermal testing is not appropriate for every child with a suspected allergy. Your child's consultant will assess their symptoms, medical history, suspected allergen and previous test results before deciding which investigations are most suitable.
For more information, visit our Paediatric Allergy service page.
More information
Your allergy consultant may recommend intradermal testing if you have experienced a suspected allergic reaction and initial investigations have not provided a clear explanation.
For example, intradermal testing may be appropriate when investigating selected suspected drug allergies (penicillins, local anaesthetics, general anaesthetics, for example), depending on the type of reaction and the medicine involved. Similarly, if you have experienced a reaction following an insect sting, but your initial allergy tests have been negative or inconclusive, your consultant may consider further testing.
Intradermal testing is not generally the first test used to investigate an allergy. Skin prick testing and specific IgE blood tests are often considered first, depending on the suspected allergen and your clinical history.
At Welbeck, intradermal testing is performed by an allergy consultant.
The test itself typically takes around 15 minutes, although your overall appointment may be longer to allow for consultation, assessment, and any necessary monitoring. Your team can confirm the expected duration for your appointment.
During the procedure, your consultant will:
1. Review your medical history: discuss your symptoms, previous reactions, and the results of any earlier allergy investigations.
2. Select the appropriate test: determine which substance or substances should be tested and the appropriate concentrations.
3. Prepare the testing area: usually on your arm, where the skin can be examined easily.
4. Administer the test: inject a very small amount of diluted substance just beneath the skin's surface.
5. Assess the skin's response: examine the injection site after the appropriate interval for signs such as redness, itching, or raised swelling.
6. Interpret the findings: consider the results alongside your symptoms, medical history, and any other relevant tests.
More than one injection may be required, depending on the investigation.
The skin's response can provide useful evidence of sensitisation, but a positive result does not necessarily mean that you have a clinical allergy. Your consultant will explain the findings and whether any further investigations are needed.
In many cases, the initial results can be discussed during the appointment. The timing and interpretation will depend on the test being performed and the clinical question being investigated.
Intradermal testing is performed under specialist supervision because it can cause an allergic reaction. The risks depend partly on the substance being tested and your medical history.
Possible side effects include:
temporary redness at the injection site
itching or localised swelling
mild discomfort where the injection was given
a more widespread allergic reaction, which is uncommon but can be serious
Intradermal testing can provoke a stronger response than skin prick testing because the substance is injected into the skin. A positive result can also be less specific, meaning that the test must be interpreted carefully.
Before proceeding, your consultant will assess whether the potential benefits of testing outweigh the risks.
Tell your consultant or a member of the clinical team immediately if you feel unwell during the procedure. They can assess your symptoms and provide treatment if needed.
Your consultant will explain whether you need to prepare for your appointment. Some medicines, particularly antihistamines, can suppress the skin's response and affect test results. You will need to stop antihistamines for at least 48 hours before testing.
Do not stop taking prescribed medicines unless your treating clinician has advised you to do so. Your consultant will explain which medicines, if any, need to be avoided and when any changes should be made.
Before your appointment, it may be helpful to bring:
a list of your current medicines and supplements
details of previous allergic reactions, including when they occurred and what may have triggered them
results of previous skin prick tests or allergy blood tests, if available
details of the medicine or insect sting suspected of causing your reaction
information about any other medical conditions that may be relevant
Your clinical team will provide any additional preparation instructions. Follow their advice about eating, drinking, and your usual medicines before attending.
Most people can return to their usual activities after intradermal testing, once the clinical team has confirmed that it’s appropriate to do so.
Mild redness, itching or swelling around the injection site may occur. These local reactions generally settle without treatment, although the time they take to resolve can vary.
Your consultant will advise whether you need to remain under observation after testing and when it’s safe to leave. Follow any individual aftercare instructions you are given.
Your consultant will explain the results in the context of your symptoms and medical history. If further investigations are needed, they’ll discuss the appropriate next steps with you.
The test is covered by most private medical insurance (drug and venom allergy). If you have private medical insurance, please contact our team to clarify the coverage of any consultation or other services associated with your assessment before proceeding.
Our team can explain the appointment process, the cost of testing and any other relevant charges before you book.
At Welbeck, intradermal testing is performed by an allergy consultant as part of a specialist assessment. This allows your consultant to consider your symptoms and medical history when selecting the appropriate investigation and interpreting your results.
Allergy testing requires careful interpretation. Your consultant will explain what your results mean, whether they support a diagnosis and whether further investigation is needed.
Where appropriate, your consultant can recommend additional tests or coordinate care with other specialties within Welbeck. This helps ensure that decisions about your diagnosis and management are guided by your individual clinical needs.
Intradermal testing cannot be booked directly without first having a consultation with the allergy consultant who would perform the test. Your initial consultation allows the consultant to review your symptoms, medical history and previous investigations and decide whether intradermal testing is appropriate.
If you would like to arrange an appointment, contact our Allergy centre to discuss the referral process, appointment availability and costs.
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Frequently asked questions
Welbeck offers paediatric allergy appointments for children aged 0 and above. However, intradermal testing is only rarely needed for children with a suspected drug or venom allergy.
Your child's consultant will consider their symptoms, medical history, suspected allergen and previous test results before deciding whether intradermal testing is appropriate.
Intradermal testing involves injecting a small amount of a diluted substance beneath the skin. It is used in selected investigations of certain medicine and insect venom allergies.
Patch testing does not involve injections. Small amounts of potential allergens are placed on patches that remain in contact with the skin for a specified period, with readings taken at appropriate intervals. It’s commonly used to investigate allergic contact dermatitis, which causes delayed skin reactions following contact with a substance.
Your consultant will recommend the appropriate test based on your symptoms and suspected allergy.
No. A positive intradermal test indicates that your skin has responded to the substance being tested, but it does not necessarily confirm a clinically significant allergy.
Intradermal testing can produce false-positive results, so your consultant will interpret the findings alongside your symptoms, medical history, and other relevant investigations.
The aim is to establish whether the result is consistent with your clinical history and whether any further investigation is needed
Intradermal testing can detect a skin response in some cases where a skin prick test has been negative. This is because the two tests introduce the suspected allergen into the skin in different ways, and intradermal testing can be more sensitive in certain clinical situations.
However, intradermal testing is also less specific and can produce false-positive results. A positive result does not automatically confirm an allergy.
Your consultant will decide whether intradermal testing is appropriate based on your symptoms, the suspected allergen and your previous test results.
Not necessarily. Intradermal testing can be more sensitive in certain situations, but it is less specific and has a greater risk of provoking an allergic reaction than a skin prick test.
The most appropriate test depends on the suspected allergen and your medical history. Your consultant will select the investigation most likely to provide useful information while considering the associated risks.
In many cases, your consultant can explain the initial skin-test findings during your appointment. However, the interpretation and any further investigations required will depend on the suspected allergy and your clinical history.
Your consultant will discuss the findings with you and explain the next steps, including whether additional tests or follow-up are needed.
No. Intradermal testing is not used to diagnose food or pollen allergy.
For suspected food allergies, assessment involves a detailed clinical history and, where appropriate, skin prick tests or specific IgE blood tests. In some cases, a medically supervised oral food challenge may be needed to confirm the diagnosis.
For suspected pollen allergies, skin prick testing and specific IgE blood tests are the usual methods of investigation.
Your allergy consultant will recommend the most appropriate tests based on your symptoms, medical history, and suspected triggers.