Losing Hair On Inside Of Back Legs Only????

[pete young]

I have a female that has lost the hair on the inside of both of her back legs and nowhere else. It is uniform on both legs. The skin looks a little irritated, but she doesn't act like it bothers her. Any ideas what might be going on?

[FetchingPixels]

What about food allergies? I'm not sure if it matters where they lose hair from?

I thought Oh i'll buy my dogs these all natural peanut butter treats, it will be good for them! I was feeding them tons of them (they were small) turns out my female dog is allergic to them and lost patches of hair off her stomach.
Not sure if it's the same thing or not.