What is the red rash
like? Does it have water filled boils? is it following a particular pattern?
i would advise you to go see a dermatologist
who could tell you after a physical exam what is the exact cause for this pain, burning and rash.
It could be herpes zoster
as sometimes in this condition the pain and burning precedes the rash. But cannot be sure without looking at it.
You can apply a cloth soaked in cold
water till then if the burning and itching continues.See the dermatologist immediately to reduce the severity of the problem.