Dermatology Associates of Morris

Patch Testing Procedure

Scheduling

3 separate appointments will be required for application and evaluation of the test sites. If you are scheduling by phone, be certain to inform our staff that you have been instructed to schedule "patch testing". It is important that you schedule all 3 of the required appointments, that you keep them (i.e. do not cancel) and that you arrive on time. These appointments include:

An initial test application appointment with a member of our nursing staff, always on a Monday afternoon, between 1:30 - 3:00.
2 test reading appointments with one of our nurses or doctors (not necessarily yours) two days (Wednesday) and four days (Friday) after application. You should not experience lengthy in-office waits for these appointments and your visits should be of short duration. To help assure this, please save your questions for a telephone discussion with your doctor. (See "Interpretation" below)

Application

Usually 8 adhesive strips, each containing 10 patches that contain one or more chemicals, will be applied to your back or, on occasion, to an alternate site. Shower on the morning of your initial visit, but do not apply any creams or lotions to your back or arms as it may interfere with adherence of the strips. To maximize adherence to the skin, the nurse might have to shave an area prior to application of the strips. She will also place several black pen marks on your skin that serve as landmarks to note where the strips have been placed. Do not wash them off until we instruct you to do so. We suggest that you wear a dark undershirt as the black ink sometimes comes off on undergarments.

Restrictions

For the first 48 hours, do not shower or bathe, and avoid sweat producing exercise. If a test strip becomes loosened, reinforce it with adhesive tape and make a note of the site. Avoid scratching the test areas as it may loosen the strips and make interpretation difficult. Should an area become excessively itchy prior to the scheduled removal of your patches, call our office and we will instruct you on how to proceed. Once patches have been removed, you may shower, but for an additional 48 hours (until after your 2nd test reading appointment) do not use soap on the test sites, do not rub or scrub the area (avoid vigorous towel drying), and prevent excessive water from running directly onto your back. Moderate exercise is allowed.

Interpretation

A positive test is usually evident within 48 hours as a red, raised, round ¼ inch spot. Some of the patches contain dyes or tinted materials that may temporarily stain the skin. This should not be misinterpreted as a positive test. Sometimes a late reaction occurs 7 to 10 days after initial test application. If you think you’ve developed a new spot or feel itchy in an area that was not present at your final reading, please call us for evaluation.

Follow Up