Skin prick allergy test

Your Healthcare Professional has referred you for this test to help find out whether or not you have an allergic response to specific triggers. 

These triggers, known as allergens, may be particles in the air such as tree pollens, grasses, dust mites or moulds. They may also be food products such as nuts, eggs or milk.

Before you attend for your skin prick allergy test, there are certain medications that you should not take, which could interfere with the test results. If you are unsure about which medication you should not take, please contact the department. 

Do not take:

• Antihistamines (1st generation) e.g. Chlorphenamine (Piriton) for 2 days
• Antihistamines (2nd / 3rd generation) e.g. Cetirizine, Loratadine, Fexofenadine for 7 days
• Steroid cream (applied on the forearms) for 7 days
• Omalizumab (Xolair) - please contact the department

The allergens are manufactured into liquid solutions, which can be introduced to the skin on the forearms. Which allergens we use, depends upon what your Healthcare Professional asks us to test for. In rare cases, you may be asked to bring certain foods to the appointment with you. Your appointment letter will tell you if this is the case.

1. The forearm is used as the test site, and the skin is prepared by marking where each allergen will be located.
2. Small droplets of allergen solutions are placed onto the forearm. 
3. Then a small lancet is used to prick through the allergen. This allows the allergen to pass through the top layer of skin.
4. We can then measure any response to each allergen. Visual responses, in the form of a small lump (weal) and reddening (flare) are usually measured using a ruler between 10 and 15 minutes after the prick.
5. You will then be monitored until any visible response (weal and flare) has reduced.
6. Following the procedure, anti-histamine cream may be applied to the test site to help reduce the response.

Please expect to be in the department for between 20 and 60 minutes. Children are often monitored for longer periods following the test.

No, the test does not hurt. The procedure is similar to a very tiny pin prick, which is not deep enough to draw blood. Whilst it does not hurt, small children may experience slight discomfort to the procedure. Should the test produce a weal and flare, this may feel itchy. Anti-histamine cream applied following the test should reduce this.

Skin prick allergy tests are very safe. Whilst extremely rare, anaphylaxis (significant allergic reaction) is possible. In the unlikely event that this does occur, medical professionals are available to provide the appropriate treatment.

If you have asthma/hay fever, it is possible that you may get asthma/hay fever symptoms in the hours following the test. Again, this is rare, but please ensure you have your reliever inhaler or hay fever medication with you.

The results will not be ready straight away as they will need analysing and processing. They will be passed on to the healthcare professional who referred you for the tests and should be available for your next clinic appointment.

If you are unable to attend the appointment that has been arranged for you, please contact the department on 01709 424572 as soon as possible so that we can organise another appointment for you, and offer your appointment time to another patient on our waiting list.

You can choose whether or not to have the tests, but if you do choose not to complete them, important information may be missed which may impact on receiving an accurate diagnosis and treatment.

Respiratory and Sleep Physiology 

01709 424572 
Monday to Friday, 8.30am to 4.30pm
Email: rgh-tr.medical.physics@nhs.net