I have a rash on the top right side of my back, is it something serious?

I have a rash on the top right side of my back. I am sending a photo. I felt a slight burning and itching sensation for a couple of days and now have a burning rash about 5 inches long. It burns and itches a lot and doesn’t look good. Is it something serious?

Age: 56
Female
Medications: nexium