What Causes Itching On The Breast And Nipples?

I am 58, post-menopausal, and occasionally have itchy breasts/nipples. The itchiness can affect one or both breasts, almost always at night. I never noticed it until I began Lipitor a year ago. I was on Lipitor for awhile when the symptoms disappeared. They reappeared when my insurance company insisted I take Simvastatin. I began Simvastatin last October and also had a mammogram(and breast exam) which was normal. I saw my general practitioner today who examined the breasts for changes in skin, coloration, etc. and there are none. Could these symptoms be related to the statin? My doctor suggested I stop the statin for one month to see what happens. I am aware of inflammatory breast cancer and will be watching these itchy symptoms closely this month. Have you ever heard of any connection to simvastatin?