Benadryl

I'm having some kind of weird reaction. My torso intches SO bad! I have never felt anything like this! It feels like hives, but I don't have hives. I don't have a rash or bites, or anything! It just doesn't itches! If I scratch it (which is really hard bit to do), it just hurts. I'm thankful for Benadryl, which at least makes the itch a little better. I would really love to know what is causing it so I can make it stop!