security would allow it thru?
Yes
"Medication in liquid form is allowed in carry-on bags in excess of 3.4 ounces in reasonable quantities for the flight. It is not necessary to place medically required liquids in a zip-top bag. However, you must tell the officer that you have medically necessary liquids at the start of the screening checkpoint process. Medically required liquids will be subjected to additional screening that could include being asked to open the container."
Regarding medication, speak to your doctor. If you do go with Benadryl, make sure to test it before the flight, as it can have the opposite affect, which is not something you want to find out on the flight.