It may be a staph infection then (not shiingles). I would try applying the Neosporin or triple antibiotic ointment as directed on the tube and see it if it starts to heal in a couple of days. You may want to wash your pants, shirt and towels etc. if any were in the area of this infection. Let me know how it goes. Obviously, you can always have your doctor look at it but this is my opinion.
mkh9
In the middle usually. Small, but this time it has two areas at once.
It may be a staph infection. Sometimes you can also get a mixed infection such as staph with strep. It can look like a rash. I would see you doctor for this. It may recur due to reinfecting yourself. Is it a small area or lage area and is it on one side of the back or both?