Answer:
48 hours
Step-by-step explanation:
Patch testing is a method to test the allergic reactions called contact dermatitis caused by the allergens found in the environment the patient is surrounded by like home allergens or work allergens.
To perform the test, the allergens are placed on the metal discs which are pasted on the back of the person with hypoallergenic tape.
Then the discs are allowed to be pasted on the back of the person for about 2 days or 48 hours after which the skin is examined for the allergy reactions caused by an allergen in the form of inflammatory response or hypersensitivity.
Thus, 48 hours is the correct answer.