What's up with my pony's face?

Hi everybody! Got a question for the community here, hope it's something simple but we can't really put a finger on it. Our 5yo pony just started losing some hair on her face only. Our first thought was rain rot but it's very localized to her face only and her skin doesn't appear irritated. It's literally just patchy hair loss.

We're thinkiydry skin or maybe the bridal was rubbing too much? Any ideas would be greatly appreciated!