Prepare for your Derm Patch Testing Visit

Preparing for a Patch Test

  •  Getting the skin ready for your patch test is important.  Following these instructions will help you to get more accurate, reliable results. 
  •  Do not use topical medicines (creams and ointments) on your back and any other area where patches may be placed for at least 1 week before patch testing.  You can continue to use your medications to areas of the body where patches will not be placed.
  • Avoid sun exposure for 1-2 weeks before patch testing. 
  • Continue to use moisturizers on the skin until the day before patch testing.
  • Continue to take your prescribed antihistamines as you normally would before and during the testing.

What Happens During a Patch Test?

  •  You will need to come to the clinic 3 times during the week that your patch testing is done.  Generally the test lasts for 5 days total.
  •  It is important to follow the guidelines below to get accurate results.  Remember, that patch testing is evaluating a slow, delayed skin reaction so it is important that the patches stay in place and the test site be protected throughout the entire test.

Throughout testing:

  •  The patches and test area marked with ink must be kept dry throughout the entire test!  No showers or tub baths are allowed.  Sponge baths avoiding the test area are ok.
  • Do not apply anything to the test area.  This includes all soaps, creams, ointments and moisturizers.
  • Do not scratch, rub, loosen or remove the patches.  Avoid scratching the test site even after the patches have been removed by your nurse.
  • Avoid physical activities that will loosen the tape
  • Do not expose the test area to sunlight.
  • Avoid hot areas and activities that cause excessive sweating.
  • Continue to take your prescribed antihistamines

The First Visit:

  •  Small sheets, or patches, holding different substances are placed on the skin.  The nurses will use a marker to outline the edges of the sheets.  Then, the sheets will be secured with tape or other sticky dressings.  The patches are usually placed on your back and left in place for 2 days. 
  •  Wear loose, comfortable clothing.  Wear old, darkly colored clothes to avoid stains from the marker.
  •  Remember that the patches must be kept dry!   Do not take a shower or bathe where the patches are.  Do not apply creams, ointments, or moisturizers where the patches are.  Do not scratch, pull off, or remove the patches.  Avoid hot areas and activities that cause excessive sweating.
     

The Second Visit:

  •  The second visit is 2 days after your patches were put on. The nurses will carefully remove the tape and patches.  They will re-mark the skin where the patches were.  The nurses will check the area to see if the skin shows any signs of a reaction.  In many cases a reaction may not have shown up yet.  It is still important to come back to the clinic to have the area checked one more time.
  •  Wear loose, comfortable clothing.  Wear old, darkly colored clothes to avoid stains from the marker.
  •  Continue to keep the skin where the patches were dry!   Do not take a shower or bathe where the patches were.  Do not apply creams, ointments, or moisturizers where the patches were.  Do not scratch the skin where the patches were.  Avoid hot areas and activities that cause excessive sweating.
       

The Third Visit:

  • Your third visit is usually 4-5 days after your patches were put on.  You will come to the clinic to have your skin checked.  It is important to check your skin again to look for late or delayed skin reactions.   The nurses and doctor will look at your skin and tell you if there are any substances that you should avoid. 
  • After your visit you can restart all of your topical creams, ointments, and moisturizers.  You can shower and bathe normally at that time.