Dear Johanna,
What you described with this mom sounds like a derm problem and not
necessarily directly related to breastfeeding. I would recommend that she
see a dermatologist.
There was a good article in the JHL a few years ago on nipple problems by
Kathleen Huggins. She works with a dermatoligist and they described a
similiar case. Since this has been slowly progressing the last several years
I would encourage making this appointment before guessing at the diagnosis
and self treating.
Good luck.
Ann Perry RN IBCLC