Mouth peeling / mucosal sloughing help

Please, I’m at my wits end - has anyone had the inside of their mouths peeling and changing toothpaste was NOT the answer?

I’ve tried checking for trigger foods, drinks, toothpaste and while certain foods make it worse it seems to be almost entirely random

Mine used to come and go for months at a time but for the last couple of years its almost constant

I’ve tried several different toothpastes. I don’t use mouthwash. Its not that.

Some antihistamines seem to help a little but not entirely.