Contact dermatitis is a skin condition caused by irritants (irritant contact dermatitis) or an allergy to substances (called allergens) which come into contact with the skin (allergic contact dermatitis). Allergens include products at home, at work or in leisure activities. Identifying the causative agent can help you implement ways to avoid it. Patch testing is a specialist procedure carried out by dermatologists.
How Is Patch Testing Performed?
Patch testing is a specialist procedure carried out by dermatologists that helps define if you are allergic to certain allergens. At GK Dermatology, we use the T.R.U.E test, a convenient and ready-to-use patch test that includes 36 common allergens. T.R.U.E test identifies reactions to metals (nickel, gold, cobalt), fragrance, preservatives, topical antibiotics (neomycin, bacitracin), wool alcohols, black rubber mix, and topical steroids, among others. Three visits to Dermatology are required. On day one of testing, 3 patches (12 allergens placed on each) are attached on the patient’s upper back (see picture on the right). Patches are fixed in place with non-allergic paper tape. Patient returns to the office in 48 hours, the patches are removed, and the first reading takes place (skin is examined to see if there is a reaction to any of the tested substances). Patient needs to return 2-5 days later for a second reading (determines whether a delayed reaction to any of the allergens can occur).