What is Patch Testing?
A test to assess your skin’s allergic reaction to a variety of substances. The test consists of allergens which will be placed on special paper and adhered to your back with hypoallergenic tape. There are NO needles used in this form of allergy testing. The entire back is covered with tape.
In order to obtain the most optimal results, there are a few requisites:
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The back must be clear of rash
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Certain medications are not compatible with patch testing and may interfere with results. Patch testing cannot be done while a patient is on a systemic steroid such as prednisone or recent topical steroids to the back. Please report all medications to the physician’s attention prior to scheduling patch testing. Patch testing cannot be done until 4 weeks after an intramuscular cortisone shot.
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Patches may slip if the back gets wet or sweaty. We ask that you refrain from showering while the patches are in place for 2 days (instead sponge bath) and refrain from activities that may make you sweat.
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Exercise and other activities that may loosen the patches are discouraged.
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Avoid exposure of the back to sun for 1 week prior to the visit. Patches cannot be placed on a back with excessive sun exposure or sunburn.
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To avoid catching or tearing the edges of the tape, wear a T-shirt or pajama top to bed.
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If the back is hairy, the patches will not adhere. Please have your back shaved prior to the visit.
How does Patch Testing work?
Patch testing is performed over 3 visits to our office.
Monday:
Patches are placed on the back on the first visit. The patches are marked and then hypoallergenic tape is placed over the back.
Please take care to avoid getting the back wet or sweaty until the patches are removed. Sponge bath and avoid strenuous exercise.
Antihistamines such as loratidine (Claritin), cetirizine (Zyrtec), fenoxidene (Allergra), levocetirizine (Xyzal), diphenhydramine (Benadryl), and hydroxyzine can be used for itch at the recommended doses.
It may appear there is red or purple behind the tape. Some of the allergens are colored and this is likely the colored dye coming through, not bleeding.
There may be mild discomfort or itching associated with a positive reaction or due to the tape on the patch. If you develop systemic symptoms, please remove the patches and seek immediate medical attention.
Wednesday:
Patches are removed at the office and a first interpretation is made. You may have to wait 15 minutes or so after the patches as the back may be very red and interpretation may be difficult.
Showering can be resumed after the patches are removed, but be careful not to let excessive water or any soap touch the back. (Wash hair leaning forward).
Friday:
Results of the test are interpreted and discussed at length.
Typically, the American Contact Dermatitis Society Core Series (88 allergens) are placed. Please let us know if you want an estimate on cost (479-876-8550) or you can ask your insurance with CPT code 95044 x 88.
For More Detail
Patch testing helps us figure out which substances may be causing your rash. It’s a safe, effective tool for diagnosing contact dermatitis.