Skin Patch Testing
What Is Skin Patch Testing?
Skin patch testing is performed to detect the presence of allergic contact dermatitis (Type IV hypersensitivity). This procedure involves applying patches with test substances in small chambers to a patient’s back. The allergic reactions usually appear 2-4 days after applying the patches and thus patients are seen in the office for a total of 3 visits (one visit to apply the patches and then two follow up visits).