What Causes Redness In Creases Of Both Ends Of Both?

Hi. I have red skin in the creases at both ends of my mouth. They don't look like a rash.Two doctors, my nephrologist and my PCP, said it could be due to lack of Vitamin B-12. I take Vitamin B-12 daily 2500 mcg and Vitamin B-12 (generic form) injections (1 ml) monthly.I have tried Neosporin, anti-fungal cream, and more. While I have ha seen a little improvement, it is still bothersome and tender to touch at times.Thanks for any suggestions. Oh, I only have minimal healthcare and cannot afford to see a dermatologist at this time. Thanks again.