User blog comment:Dominic1743/“The Heroes' Journey” Discussion/@comment-44905711-20200124024009/@comment-108.36.76.116-20200125223639

I agree that regular healing from Castie explains the no scar thing. There are times when they have injuries that take time to heal, and they don't seem to bother Castiel for small stuff. When Charile asked for help with her Carpal tunnel,, Castiel healed that, and several other small things at the same time, Including a small nick on her forehead. So if Sam or Dean need a big heal for a serious wound, it might heal the small stuff too. It might also help them not get sick.