bad nerves can do that!!! maybe you need to relax a little.. or maybe the hives!
With you having the chills and an itchy rash on your neck sounds like your body is fighting something - and that could be a bacterial infection.
Have you been near any plants that have touched your neck, been stung, bitten or scratched? You can get allergic reactions to all that as well as getting a bacterial infection from an insect sting, scratch or bite.
Having the chills can be from a viral or bacterial infection. You don't always get a high fever.
Make an appointment with your doctor so that he can identify what it is that is causing this (and rule out scabies or other problems), so that you can receive the correct medication if required.
Sounds like it could be stress related. I would mention it to your regular dr. Stress can do some crazy things to the body.