How many days prior to my appointment should I stop taking antihistamines?
Generally you need to be off long acting, 2nd generation antihistamines ( zyrtec, allegra, xyzal, claritin) for 7-10 days prior to your appointment.
The short acting, older antihistamines, like Benadryl only need 2-4 days.
Certain nasal sprays, containing antihistamines (Azelastine, Dymista ), will also interfere, and you would have to be off for up to 7 days.
Other allergy medications such as Nasal steroid sprays (flonase, nasacort) and montelukast (singulair) will not interfere with your testing and can be continued.
