Hi there.
This rare type of cancer usually occurs in older women (Around 50yrs and over)
I don't believe that you have this rare disease,because of your young age and because a high percentage cases of Paget's disease have an underlying breast cancer issue in the first place.However I have added a thread that deals with this condition that you might find informative.
Please click on the link below where you'll find good advice from "marsurprise"and my comment below it.
http://www.medhelp.org/posts/Breast-Cancer/paget-screening/show/1611034
As "ducky406" has suggested,please go see a dermatologist for treating your problem which I think is most probably a skin issue.
Take care...