patch test n a test for determining allergic sensitivity that is made by applying to the unbroken skin small pads soaked with the allergen to be tested and that indicates sensitivity when irritation develops at the point of application compare INTRADERMAL TEST, PRICK TEST, SCRATCH TEST
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a test to discover which allergen is responsible for contact dermatitis in a patient. Very low concentrations of common allergens (and any substances suspected of causing the dermatitis in the individual patient) are applied under a patch on the back. The patches are removed after 48 hours and the underlying skin is examined then and again after a further 48 hours. A positive test will show an eczematous reaction. The commonest allergens are nickel in women and chromium in men.
Medical dictionary. 2011.