Allergy Intradermal Skin Testing Make an Appointment Ask a Question Refer Patient What is allergy intradermal skin testing? How do you get ready for the test? What is done during the allergy intradermal skin testing? How long will the test take? How do you get to your test? What is allergy intradermal skin testing? Your doctor has suggested you/your child have this test as part of the evaluation at National Jewish Health. Intradermal skin tests are done to help identify if you/your child are allergic and what you are allergic to. How do you get ready 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 some of these tests and need to be stopped before the testing is done. If the medicine is not stopped before the test we will not be able to complete the test. Stop these antihistamines for the length of time listed before your appointment at National Jewish Health. Stop these oral antihistamines for 5 days before your appointment: Allegra® (Fexofenadine) Atarax®, Vistaril® (Hydroxyzine) Zyrtec® (Cetirizine) Stop these oral antihistmanines for 3-4 days before your appointment: Actifed®, Dimetapp® (Brompheniramine) Benadryl® (Diphenhydramine) Chlortrimeton® (Chlorpheniramine) Claritin® (Loratadine) Clarinex® (Desloratadine) Phenergan® (Promethazine) Tavist®, Antihist® (Clemastine) 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. Stop these medications the night before your appointment: Singulair® (montelukast) Accolate® (zafirlukast) Stop these medications the morning of your appointment: Zyflo® (zileuton) Tagamet® (cimetadine) Zantac® (ranitidine) Pepcid® (famotidine) Axid® (nizatidine) Sometimes antidepressants can also act as an antihistamine. Let your doctor know if you are on any antidepressants before your skin testing. Continue to take all your other medicine as you usually do. What is done during the allergy intradermal skin testing? When you have intradermal skin testing done, a small amount of each thing you may be allergic to (allergen) is injected under the skin. If you are allergic to an allergen, you will get a bump and redness where the allergen was injected. 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 skin test results with your history of symptoms. How long will the test take? Intradermal skin testing often takes 30 to 40 minutes to complete. How do you get to your test? Adults - On the day of your scheduled test, report to the skin testing area in the Adult Clinic. If you are an adult patient and have questions please call 303.398.1355. Children - On the day of your scheduled test, report to the skin testing area in the Pediatric Clinic. The pediatric clinic is on the second floor of the Gaulter Building. If you are a parent of a pediatric patient and have questions please call 303.398.1355. Get directions to and see a campus map of National Jewish Health. This information has been approved by Richard Weber, M.D. (May 2006).