What Causes Pus Filled Blisters On My Breasts?

I have a dumb question i have had for years tiny brown spots that show up on my breast not the nipple. Then some get a head like a pimple. when i get the pus out it wont heal until i pull what seems to be hairs out sometimes one or two other time as many as five or more. what is this? It wont heal until i get all of the hair or skin tissue out then it leaves a bad scar