Good to knowOne result rarely tells the whole story. Your provider looks at your results together with your symptoms, exam, and other tests.
What the test is
It's different from skin prick testing for hay fever and food allergies.
Why it's done
- Recurring itchy rashes where things touch the skin
Getting ready and what happens
- Avoid steroid creams on your back and sun exposure for a week before. Antihistamines are usually OK.
How the test is done
- Patches with small amounts of substances are taped to your back for 48 hours; your skin is checked at 2 and 3 to 7 days. Keep your back dry.
What the results mean
Positive reactions
You'll get a list of products and ingredients to avoid.
Questions to ask your provider
- What do my results mean for me?
- Do I need to repeat this test or have other tests?
Related conditions
Related medicines
Related tests
Sources
Last updated 2026-11-13.