V.T.
Sounds like what I had, but I didn't let it go 4 weeks. I was 3 weeks away from my due date and went to the doctor immediately. He put me on Valtrex (the Herpes medicine) and the itching stopped within a few days and scabbed over in a week. Be very careful, it can be contatigious. The worst thing you can do for Shingles and will make the problem worse is to use a Hydrocortizone cream, which we often use for rashes.