What Is The Treatment For Hives All Over The Body?

A few days ago I started to break out in hives all over. This is the second or third time that this has happened, and I wasn't sure what the trigger was. This time i believe it was because i used a latex condom, which i don't do often. I have been taking 1 zyrtec a day for two days now, in addition to benadryl several times a day. The hives seem to be almost gone now, but i have a strange tightness/pain in my chest. Should I still be worried about anaphylactic shock, after a few days?