What is patch testing?
Patch testing is a method used to detect whether you are allergic to a specific substance or substances by contact. Clues that you have allergic contact dermatitis include eczema-like rashes that don’t go away, itching on the face and/or eyelids, or reactions to products. We are looking for things that you may have been exposed to such as fragrance, preservative in cosmetics, metal from jewelry, and other chemicals in household items, that may be causing skin problems. Patch testing has nothing to do with allergies to ingested substances, i.e. food or medication; it is solely for skin-based allergies.
How does patch testing work?
Because we are looking for allergies via contact exposure, the test is done by placing a panel of 80 allergen on stickers onto your back and observing for any skin reactions over the following 2-5 days.
What is the procedure for patch testing?
Day 1: Patches are placed on clear skin on your back and worn continuously.
Day 3: Patches are removed in the office. The doctor checks for skin reactions and interprets the findings. Reactions are graded based on severity, and not all skin changes connote an allergy. The doctor will interpret the findings carefully.
Day 5-6: Third office to detect any delayed reactions. Some substances only cause allergic reactions after several days.
Why is patch testing important?
Many patients report extreme difficulty managing their chronic skin irritation, and are not sure whether they are causing contact dermatitis by using their everyday products, be it cosmetics, perfumes, nailpolish, household products, even jewelry. Many cosmetic products contain dozens of chemicals, many of which are known allergens. To learn more about allergic contact dermatitis click here.
For more information please call 212-249-8118.