"Hyakkimaru is a young man who lacks 48 body parts because they were taken from him by demons before birth…" MAL.net
He doesn't have skin or other facial features. This is him as a new born, so I'd say you're partially right with both.

When I first read that the demons took body parts I somehow imagined he'd at least have kept his skin and nose and lips, maybe one eye if he was lucky
They really picked him clean