Patients are frequently given instructions to avoid allergy medications for a period of time prior to allergy testing. Why would this be important?

Answer 1

Allergy medications block the immune response. Testing for allergy relies on the immune system acting fully without being blocked by medications. If someone is taking an allergy med, then the testing may appear negative when they are actually positive. If you'd like greater detail, like anti-histamine vs steroid effects, I'd be happy to tell you more!