Allergy Prick Skin Testing
Prick skin tests are done to help identify if you/your child are allergic and what you are allergic to.
Preparing for the Test
Please follow these directions when getting ready for this test. Check with your/your child’s doctor before you stop the medicine. All antihistamines will effect the results of these tests and need to be stopped before the testing is completed. If the medicine is not stopped before the test we will not be able to get an accurate result.
Stop these antihistamines for the length of time listed before your appointment at National Jewish.
Stop these oral antihistamines for 5 days before your appointment:
- Claritin® (Loratadine), Allegra® (Fexofenadine) Clarinex® (desloratadine)
Stop these oral antihistamines for 3-4 days before your appointment:
- Actifed®, Dimetapp® (Brompheniramine)
- Atarax®, Vistaril® (Hydroxyzine)
- Benadryl® (Diphenhydramine)
- Chlortrimeton® (Chlorpheniramine)
- Phenergan® (Promethazine)
- Tavist®, Antihist® (Clemastine)
- Zyrtec® (Cetirizine)
- Actifed®, Aller-Chlor®, Bromfed®, Drixoral®, Dura-tab®, Novafed-A®, Ornade®, Poly-Histine-D®, Trinalin® (Combination medicines)
If you are taking an oral antihistamine that is not listed stop the medicine for 3-4 days before your appointment. If you are not sure if the medicine you are taking is an antihistamine ask your doctor. Some over-the-counter cold and flu medications contain an antihistamine, so be sure to read labels carefully.
Stop this medicine the night before your appointment:
- Singulair® (montelukast)
- Accolate® (zafirlukast)
Stop these medicines the morning of your appointment:
- Zyflo® (zileuton)
- Tagamet® (cimetadine)
- Zantac® (ranitidine)
- Pepcid® (famotidine)
- Axid® (nizatidine)
Antidepressants known as tricyclics as well as some sleep aides can also affect the results of your skin testing. Let your doctor know if you are on any antidepressants or sleep aides before your test.
Continue to take all your other medicine as you usually do. Inhaled, nasal and oral glucocorticoids (steroids) will not interfere with the results of your skin testing.
Do not apply lotions or creams to your back the day of your appointment.
During the Test
When you have prick skin testing done, a small amount of each thing you may be allergic to (allergen) is placed on the skin (usually your back). The skin is then pricked. If you are allergic to an allergen, you will get a bump and redness where the skin is pricked. After a short time, each skin test reaction is measured for swelling and redness. A large enough skin reaction is a positive skin test. This means an allergy may exist to the allergen placed at that site. Your doctor will compare your prick skin test results with your history of symptoms.
Length of the Test
Prick skin testing often takes 30 to 40 minutes to complete.
Retrieved from: http://www.nationaljewish.org/programs/tests/allergy/prick-skin/