This sounds like the same thing my mother had and it ended up being Pagets disease, which is a rare form of breast cancer. My mom's primary doctor blew it off as just a rash it wasn't until she went to a dermatologist and they did a biopsy did they realize it was cancer. I suggest you get a biopsy done ASAP.
My mother's breast cancer started on her breast as a rash. It appeared to be nothing more than an allergic reaction to a detergent that got worse as time went on. Even though, my mother's cancer reoccurred with the onset of this rash, and usually, if a rash is malignant, it is because of a reoccurance, please have it diagnosed. My mother had been to the doctor for 3 years and no one ever connected this rash with cancer, she now is in the hospital, has been for months and the cancer has matastisized all over her body.
Dear pger_98: The skin on the areola is just like any other skin and can be subject to rashes or other skin problems. Rashes that occur on both areola are more likely to be related to a skin problem than any cancer related problem. However, if this rash does not go away in a week or two or if it is accompanied by scaling, bleeding, or itching, you may wish to get another opinion.