What is a Patch Test?
A Patch Test is a procedure used to diagnose Allergic Contact Dermatitis (ACD). Patch test techniques for diagnosing ACD have been used for over 100 years and the present test methods are based on the established principle of using a hapten (potential allergen) exposed to the skin via a delivery chamber.
What is Patch Testing?
Patch testing attempts to reproduce the allergic reaction on the normal skin on the upper back of the patient. You will not be able to take a shower or use any oral steroids or topical creams on the back during the patch test process. It is also important to avoid taking steroids over 10 mg for 3 weeks before your scheduled patch test.
When your provider has referred you for patch testing, you will be set up with 3 different appointments. The first appointment will be with the nurse to apply the patches. The nurse will then set you up for an appointment for 48 hours later for the removal of patches. At this visit, the nurse will remove the patches and write down any reactions you might be having at that time and schedule you an appointment to see your provider in 48 more hours. At your reading appointment, the provider will take a look at the area where the patches were applied to see if there were any positives. If so, they will provide you with a copy of the allergen with common household allergens to avoid.
The diagnostic value of patch testing depends upon the choice of test substance, the vehicle, the concentration, results interpretation and patient counseling. Patch tests are comprised of materials that occur in the home, work and/or recreational environment. Our patch tests do not test for allergens such as food, pet dander, or grass.
Patch Testing for Proper Diagnosis of Contact Dermatitis
Contact allergen skin testing is a simple and objective scientific method available to physicians to augment the diagnostic process. Often, the patch test response is the crucial piece of information that allows for the early identification of the offending allergen(s) and confirmation of a diagnosis of Allergic Contact Dermatitis (ACD) and/or Irritant Contact Dermatitis (ICD). Once a diagnosis is achieved, the patient can then take appropriate action to avoid exposure to the allergen and, if possible, substitute non-allergenic agents.
For more information on the patch testing process, please click the link to visit the Chemotechnique Diagnostics website
If you have had patch testing at our office and have confirmed positive results, please use the link below to learn where the allergens are found and what you can do to manage your contact allergy.