Stain on Nintendo Switch?

I have discovered on my Nintendo Switch such a stain goes away? And where does he come from? I have wiped the Nintendo Switch with wet glasses cleaning cloths, maybe he comes from it?

Plastic wears off when you hold it in your hands often.

Could be greasy fingers. I use a microfiber cloth that works pretty well.

So there's no way to remove the stain?

I've just tried it does not go away

Could then be erosion like the xSimonx3 wrote

You have polished the plastic at the places with your fingers bare. Had mine too and is completely normal. (Passier auhc nix bad aucsser just that it does not look so nice)

You could cover the place with a printed adhesive film or you buy yourself an exchange housing.