Allergy Patch Testing

Allergy Patch Testing Process

  • You are being patch tested to determine if your rash is caused by an allergic reaction to specific substances (allergens, such as chemicals, minerals, or medications) that may have come into contact with your skin.
  • We have tested the most common allergens in North America; but since the test cannot be comprehensive, not everyone will get conclusive results.
  • The test process will involve at least two visits to the clinic after the test is applied, to look for various degrees of redness, swelling, or even blistering at the test sites.

What to Expect

  • We have applied strips of tape with small amounts of suspect substances onto your back. This may occasionally feel uncomfortable, and you may develop itching under one or more of the chambers.
  • Try to avoid scratching, as itching is normally an indication of a positive reaction and scratching might alter the test results. If pain occurs call us.
  • Keep the area dry until the patches are removed in 2-3 days. You may take a sponge bath, but DO NOT get your back wet.
  • Avoid heavy and physical exercises that could cause excessive perspiration and detachment of the test unit.
  • If you notice patches peeling or loosening from the skin, have someone apply pressure to the adhesive portion of the strips. If necessary, you can also apply additional tape to the edges of the chamber units.
  • Abstain from taking oral or injected steroid medications; these may invalidate the test.
  • Avoid prolonged sun exposure to the test area.

Next Steps

  • The chamber units will be removed after about 2 days for the initial reading, to assess for early reactions at the test sites and mark them with ink.
  • A second reading will be scheduled in about 2 additional days to assess final test results.
  • Continue to watch the test area over the next week, in the event there is a delayed reaction on the skin.


  • Upon completion of this procedure, you will be provided with written results and advised of any skin allergies you may have.
  • We will provide you with the various names of the positive allergens and where to find them in your environment.
  • Isolating your skin allergens and avoiding exposure to them can help reduce the risk of future allergic reactions.
  • Return to see us if your skin condition is persistent or recurrent, and your doctor will provide treatment options, as needed.