Patch Testing

Instructions


Patch test is an essential investigation to identify the specific allergens triggering reactions for patients with persistent contact dermatitis. The results of the test will help patients identify safe, allergen-free products to use.

We use the North American 80 Comprehensive Series, which includes 80 common chemical allergens. The full list of allergens can be found here.

This test will take 3 clinic visits. Each visit takes around 30 minutes.

Preparation:

  • Avoid medication containing cortisone and immunosuppressant medication 2 weeks prior to the test (check with your PCP before discontinuing any medications).

  • Avoid sun exposure to your back.

  • Do not apply any lotions, creams, or fragrances to the back.


Visit 1 :
The patch test has chambers filled with suspected antigens, which will be applied to your back. This may feel uncomfortable and some itching may develop under some chambers.

  • DO NOT ALLOW THE PATCH TEST AREA TO BECOME WET. Take only shallow baths and wash hair over the sink.

  • Avoid touching the patch test area, as scratching may alter results and cause a false positive.

  • Keep patch test area dry, and wear loose clothing.

  • Avoid medications containing cortisone, prolonged sun exposure, and strenuous physical activity that can cause excessive sweating.


If you notice loosening of the test unit, have someone press firmly on the edges, and if needed, apply additional adhesive tape on the edges. If intense burning or itching occurs, call the clinic.

Visit 2 :
The first test reading will be done after 48 hours.

Visit 3:
The second reading will be done 96 hours after patch application. You will receive information about any substance(s) you may be allergic to, and advised on how to avoid these substances.

Side Effects: Patch tests are safe. You may expect some irritation and redness under the test strip.
If intense burning or itching occurs, call the clinic at (617) 804-6767.

Instructions after patch removal:

  1. Avoid wiping off markings at testing sites.

  2. You can take a shower/bath, but do not scrub your back or apply lotion/creams to patch test area.

  3. Come for your 2nd and 3rd visit to see the physician.