Zoster is a viral infection that causes a painful and blistering rash. Zoster sometimes last for 1 weak or ten day, but others may suffer for more then month, leaving behind pink healing skin.
Zoster also commonly referred to as Shingles is caused by the reactivation of the varicella-zoster virus, the same virus that causes chickenpox. After an episode of chickenpox, the virus lies dormant in your nerves and in the body. The virus may reactivate as shingles during low immune system.