First you need to determine if the problem is from something inside 
          the breast, an exogenous (external) disease, or an irritation from clothing, 
          soaps, body lotions, etc.. Any condition that originates from the inside 
          of the breast, or that may be a disease or rash from an unknown source, 
          should probably be checked by your personal health care provider. Sometimes, 
          an irritation may be caused by someone using a different soap in your 
          laundry, or by your wearing a bra that has a seam where it will irritate 
          the nipple. This can be aggravated by physical exercise that causes 
          excessive movement of the nipple against the fabric that covers the 
          nipples. In that case, a change in apparel may be in order. Do not let 
          anything like this to continue without medical attention.