If the ring is roundish but not perfectly spherical I would consider ringworm
as a possibility.  Just a thought.  It can be treated with Lotrimin cream (OTC
strength). I think that Kathleen Huggins article on persistant nipple soreness
included one case of ringworm on the breast. Sometimes ringworm can present
with a raised bumpy border.  It might not be as scaly on the breast as it is
on other places.

     Cindy N.