This rash looks very much like what I have except mine is across the abdomen and does not involve back. (I have had it now going on about 5 weeks). What is very similar to ine is that I was plagued by canker sores beginning about 2 weeks before this - absolutely pplagued where I would have 4 or 5 at a time - and they were developing back to back. I also broke out with what looked like Chelitis. I treated myself with I brushed with baking soda and rinsed with it, and rinsed with a diluted vinegar solution. After about 2 weeks the mouth problems atrated to clear up - but then there was the rash. I ahev gone over this a million times - And I am now waiting the long wait to see a dematologist. In the meantime I: Got hold of some acyclovir and take 100 mg twice daily, I rinse the rash with vinegar, wash with oilive oil soap, spray rash with Lamicil (let it dry) and then rub body lotion with latic acid over rash. I also begin each day drinking 2 table spoons of apple cider vinegar in a half cups of water and a multi vitamin with a b-complex and also a extra dose of b12 with iron & C 7 cod liver oil. I am trying anything to beat this and I am doing them all at the same time. This regime either a) works, or b) just seems to work because my body was going to get over it anyway. I am attacking this as though it can be either an autoimmune issue, a fungal infection, a bacterial infection or a viral infection. - And I am for the time being washing all my cloths without any detergent just in case it is a reaction to laundry detergent - which I think I started using a different kind about when this all started to happen.