The epicutaneous test or patch test is a provocation test or allergy test to determine whether a contact allergy is present.
The epicutaneous test is currently the only means of detecting late allergies in which there is a longer period between exposure and reaction. The allergens to be tested, e.g. nickel, are fixed on the skin for about 48 hours using a patch. To check intolerances to dental materials such as amalgam, an epicutaneous test is performed, because silver amalgam is an alloy of mercury and silver amalgam is a material used for filling therapy in dentistry when amalgam is filled.