Jenna T. Nguyen, M.D
Louanne M. Tourangeau, M.D
Hannah H. Walford, M.D
Allergy, Asthma & Immunology
1300 Crane Street. 2
nd
Floor
Menlo Park, Ca. 94025
(650) 498-6720: Nurse Line
INSTRUCTIONS FOR PATCH TESTING
“Patch testing” is done by taping “allergens” under “patches” to your back and leaving them on for 48 hours. The
patches are then removed, and under the areas examined for signs of a reaction. The back is then checked again two
days later.
On day 1, you will come to the Allergy Department to have the patch test application. You will need to do the following
steps before Day 1:
-Two to three weeks before Day 1, stop all immunosuppressive oral medications (such as prednisone or
corticosteroid pills)
-One week before Day 1, stop all of your cortisone creams, as well as creams such as Protopic and Elidel. Stop
any sun exposure to your back.
-Three days before Day 1, stop all moisturizers, lotions, or cream application to your back
Day 1: A series of allergen patches will be taped to your back
* After the patches are applied, please avoid any sweating, exercise or strenuous activity until the patches are
removed on Day 3. You can take a sponge bath only, but do not get your back wet. Showering, bathing or
swimming is NOT allowed. Too much sweat or water will lift up the patches and make them loose contact with
the skin, which will make the test useless.
Day 3: You will return to our department to have the patches removed and have the skin marked with a marker.
Any reactions will be noted.
Day 3-5: Do not rub your back with a towel and avoid scratching the area. Do not wash off the markings on your
back, as that will the test useless.
Day 4 or 5: You will return to our department for a final reading.
Day 5-7: You may bathe, but try not to wash off the markings. Some of the allergen reactions may become
positive only at this time. Of you notice any new reactions during this time, call our department to have this
examined.
