Painful mass in nipple

[mmphelps]

I have a recurring painful mass under my right nipple (would be at 3 o'clock position if i was standing in front of you and you were looking at it), accompanied by reddening of the breast skin on that same side.  The areola, in that location, is swollen and painful, but is totally normal on the opposite side of the nipple.  The mass is not a lump with discrete boundaries, but rather a firmness under the nipple that spreads as the condition worsens.  It occurred 5 months ago and cleared up right away with penicillin.  I am on the second day of penicillin now, and notice that pain is decreasing.  Could this be periductal mastitis?  Thank you for your help.

[Cleveland Clinic]

Dear mmphelps:  Without evaluation, it is impossible for us to speculate on whether this is mastitis or some other entity.  Your doctor would be best equipped to answer this question.  If it gets worse after the penicillin, you may wish to get an opinion from a breast specialist.  These are often affiliated with large academic medical centers.

[mmphelps]

i'm 38 years old, gave birth to twins 26 months ago, and stopped breastfeeding 20 months ago.