Maggie had the same thing that developed about a month after we adopted her, so she would have been about 5-6 months. We thought at first it may have been from the leash rubbing her head when we walked her. It's gone now and I'm trying to think of when it corrected itself. She got antibiotics for her belly looking red after being spayed at the same time she was treated for ringworm, so I'm not sure which one of those cleared it up.