What Causes Cluster Of Red Blisters With Itching On Chin?

I have a rash on my face to the lower side beneath my mouth. I have seen my GP twice in the last 3 weeks as nothing is working. Gp doesn t know what the rash is suspected a viral infection, or fungal or impetigo or cold sore!!I ve been given ficus in, daktacort and acyclovir nine of which gave worked. The rash is red sore sometimes itchy and has a small cluster of raised bumps. What should I do next? R Please help Thank you