What is the possible origin on my skin rash?

[Krjasmine]

I’ve recently developed some lifted skin on my back. Its origin is unknown and I am getting concerned. It’s blotchy and usually itchy. I have a history of contact dermatitis, but this looks different. It’s not a solid rash, it’s almost octagon shaped and it’s concentrated on my upper back. I’ve used toperimate cream (prescribed) but it’s not working.

[CurfewX]

It looks like toperimate can be used to control the symptoms, but if there's an underlying cause that won't self-resolve (such as contact dermatitis does), it won't do anything.

Have you considered that it could be a fungal infection, such as ringworm? You'll have to scroll down a notch, but here's the description: https://www.webmd.com/skin-problems-and-treatments/guide/fungal-infections-skin#3  It can be really itchy.  I don't know where you live, but it is more common when it's hot outside.  

[mombojombo]

How is it going?  Still got the rash?  Personally, I'd go ahead and get it looked at.  Often things can be cleared up quickly if you know what you are dealing with. Docs can prescribe a cream and bam, it starts healing.  I hate to tell you to use something OTC if it's not indicated for it.  Got access to seeing a doc?