Skin Patch Testing

ABOUT PATCH TESTING: 

  • What is allergic contact dermatitis?
    • A rash caused by direct contact with an allergenic substance. The chemicals that cause this rash are referred to as allergens and may be found in makeup, hair dye, fragrances, jewelry, topical medications, clothing, cleaning supplies, gloves, paint, shoes, etc. 
    • Allergic contact dermatitis cannot be cured, but it can be controlled if the culprit allergen is avoided 
    • Using a patch test can help determine if you are allergic to certain substances
  • What is the benefit of patch testing?
    • It is reliable, safe, and easy 
    • It can help identify potential allergens causing your rash
    • If you have a positive test, we can teach you how to avoid your allergen and offer a list of "safe" products 
  • How does patch testing work? 
    • Day 1: A panel of patches (36 of the most common allergens) are attached to your back
    • Day 3: You will return to the office and the patches will be removed. The skin will be examined for any reactions to the chemicals
    • Day 5: The skin is examined again for any delayed reactions 
  • What does a positive reaction look and feel like? 
    • Positive reactions range from mild redness with a little swelling, to bright red blistered skin 
    • Positive reactions are usually itchy 
  • What happens if I am not allergic to any of the tested substances?
    • Negative results are common (~25%)
    • Patch testing helps narrow the potential allergens
    • Please note- patch testing does not always explain the cause of the rash, and does not include environmental or food allergy testing
  • What do I need to know before my patch test?
    • Keep your back dry for the entire test period- no showering, heavy excercising, or sweating 
    • Moisture on the back will cause the allergens to run together and/or cause the patches to come off
    • Sponge bathing and washing your hair is OK
    • Do not use any oral or topical steroids on the back for at least 2 weeks 
      • Antihistamines are OK
    • Wear loose clothing 
    • Do not apply any fragrances or creams on your skin the day of the test 
    • Itching and burning are common side effects-- but DO NOT scratch