Editor: V. Dimov, M.D., Allergist/Immunologist, Cleveland Clinic
Patch test is a procedure to diagnose allergic contact dermatitis. Diagnosis of irritant contact dermatitis is based on exclusion of an allergic component.
Patch test techniques for diagnosing allergic contact dermatitis have been used for over 100 years. The current test methods are based on the established principle of using a testing material (chemical, food etc.) and a delivery device (chamber).
Patch test attempts to reproduce the allergic reaction on the normal skin on the upper back of the patient. The patches are applied and subsequently removed after 48 hours. Reactions are read after 72 - 96 hours and often, again at 7 days after removal.
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.
Commercial products for patch testing include:
- allergEAZE for Skin Patch Testing
- T.R.U.E. TEST for Skin Patch Testing
Contact Dermatitis - An Approach to Treatment (click to enlarge the image).
Patient guide to patch testing (PDF)
American Contact Dermatitis Society Core Allergen Series (PDF)
A list of allergens in the AllergEAZE test: http://buff.ly/1E6mt2Y
About Patch Testing | SmartPractice http://buff.ly/1E6mEeG