Is Benadryl Ideal In Case Of Rashes?

I have a "nervous rash." It started about a year ago.. Since then, I have not started any new medications (only on birth control..the same one I've been on for the last 4 years). When I get nervous or embarrassed my chest gets all blotchy, and my neck and face turn red. It doesn't itch. It only lasts a half hour at the most. What can I do to avoid this or treat it? I tried Benadryl before but was inconclusive as to if it really helped, or if the time frame of the rash was up and it went away on its own.