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Can antihistamines affect allergy testing?


Antihistamines like diphenhydramine, lortadine, fexofenadine, or azelastine nasal spray can potentially interfere with allergy testing. Skin reactivity may be suppressed from 28 hours to up to seven days if a patient is using antihistamines during allergy testing. Patients are advised to stop antihistamine use one week prior to testing. Let your doctor know all the medications you are currently using, including prescription and nonprescription, prior to testing.

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Answers to questions regarding information about medications or health conditions are not for diagnostic or treatment purposes and are not conclusive as to the presence or absence of any health condition. Consult your physician for diagnosis and treatment of your medical condition. The information provided is not a substitute for medical advice. Advances in medicine may cause this information to become outdated, invalid or subject to debate. Professional opinions and interpretations of the scientific literature may vary. Walgreens' terms of use and general warranty disclaimer apply to all services provided. If you are in need of immediate medical attention, contact your physician, poison control center or emergency medical professional. If you need to speak with a pharmacist for non-emergency matters, contact your local Walgreens pharmacist or call a pharmacist toll-free at 1 (877) 250-5823.

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