Final answer:
Patients must cease taking allergy medications prior to allergy testing as these medications can suppress the body's reaction to allergens, resulting in false negatives and inaccurate test results.
Step-by-step explanation:
Patients are often instructed to stop taking allergy medications before undergoing allergy testing. This is a critical step because allergy medications can interfere with the results of the tests. The medications, particularly antihistamines, may prevent the body from reacting to the allergens being tested, which could lead to false negatives. This means that even if a patient is allergic to a substance, the test might mistakenly show no reaction due to the masking effect of the allergy medication. Therefore, in order to obtain accurate results from allergy testing, allowing for proper diagnosis and treatment, it is essential for patients to follow instructions regarding medication cessation.