Shellac or Seal Coat (which is de-waxed shellac). I do not know about hypoallergenc as far as skin goes. However, they do coat pills, chocolate candies and a bunch of other stuff with it. It stays clear. It is easy to apply. If damaged by a scrape, abrasion, etc., it is very easily repaired (wipe it with DNA). It does not yellow.
Check it out on the web. Glenn uses it a lot and is more familiar with it than I am.
I have never tried it but I wouldn't be surprised if you couldn't repair an abrasion with a soft cloth and whiskey.
I'm not sure it is worth 2 cents, but that's my 2 cents worth.
First of all you have to be smarter than the machine.