Rash started on the back of the neck but has now turned into blisters that won't go away. consulted doctor took medication still didn't go away help?

Reevaluation needed: You should come back to see your doctor for re-evaluation and ask for more questions. When the initial impression and treatment do not help, your doctor can step up, try different treatment plans or refer you to a specialist. Skin rashes needed to be seen to be properly diagnosed and treated. Your local doctor is in the best position to do that.