Bearing in mind I've had it once before. Have felt a bit under the weather for a few days. This morning the left side of my face, primarily from nose across face to temple itches, tingles, feels hot as though I have a cold sore coming. I've got a splitting headache that painkillers haven't touched and I feel really miserable. I last had shingles 18 years ago around my waist and took anti virals. Could I have it again and if I went to GP could she prescribe anti virals before the rash starts?