Sore corners of mouth - No cracks or sores!?

[Countrymumma91]

What could be causing my sore corners or my mouth and a burning sensation. My tongue has a yellow coating too.

It's not oral thrush. I have no sores or cracks.

I'm so confused but I've had enough of it now 🥲

Is it angular cheilitis? I get it occasionally, I think from B vitamin deficiency.

SLS in toothpaste is a big culprit for this, especially in "whitening" and "extra fresh/extra minty" ones.