Patients who have eczema (atopic dermatitis) or contact dermatitis may have atopy patch tests done. These tests are used to determine if a specific substance causes allergic inflammation of the skin. Tiny amounts of the suspected chemicals will be applied to the upper part of the back and covered with adhesive tape. This should not be disturbed for about 48 hours, thus showering is not recommended. Your test results will be read by your allergy doctor 48 hours later. Development of redness, blisters or a bumpy rash over an area covered by a suspected allergen is a positive reaction.
Atopy Patch Tests