Nappy Rash advice?

Jodie
Any tips for clearing this up? I'm pretty sure she's teething and it came up very suddenly, not from having a wet or dirty nappy etc. She's had a lot of nappy free time, warm baths, sudocrem on at every change, she's had it for 4 days now. I should add that it's NOT painful to her, I can wipe her etc and she doesn't even flinch!