I had 3 days or so of severe burning on vacation.

I still get them, but not very often any more.

I don't know why either. Sometimes I think it is stress.
Sometimes connected to what I ate that day.

Example. We had a perch lunch on vacation at a local restaurant, my son and I.
We were surprised at how large the portions were too. Perch is expensive and sometimes in short supply up there. (lake perch).
But it tasted fine, so we didn't think about it. It was very lightly breaded and fried, but wasn't greasy.

Both of us by 5pm had burning feet. I took a brief nap and he went hiking on the shore taking pictures of the wildflowers and unusual lichens on the rocks etc. He does ultra close ups.
Like this photo from 2011...
Fringed Gentian (rare) and wild asters

Anyway he came home with burning feet. And mine were doing the same. So I suspected old fish...that is a prime histamine maker, and perhaps some MSG because it is a restaurant. So I got out the AlkaSeltzer, and bingo in 15minutes both of us had the burning resolve. He doesn't have PN either. But he has had some mild carpal tunnel problems when he plays guitar too much. So who knows? He might be on a path that will become PN some day.

So for me at least some burning is often due to something I ate previously that day or the day before.

Have you tried an antihistamine like Benadryl at night? Sometimes that helps too.