There are a lot of skin conditions that can be caused by diabetes and there are a lot of skin conditions that the non diabetes population can encounter.
Best to get medical advice and get the right treatment. It may be that you need some emollient or just general advice.
I would suggest that you do not use scented bath/shower products until you have been seen by your G.P. Try not to scratch as this may spread the rash.
If you google - skin rashes and diabetes- most sites come up with the ones that are known about.