Gold Bond's Extra Strength Medicated Body Powder will keep that area dry and clean while it's healing and prevent the spread of the breakout. Always apply this in the morning before exercise, hot weather etc- anytime you might accumulate cleavage perspiration. It only takes 10 min for sweat to go rancid on your skin. Don't put any body butters or creams on your chest (or bum!)

Applications of salicylic acid cleanser and toner, like Clean and Clear or Stridex pads, will help.

Unfortunately skin is too thick on the body for other active ingredients to penetrate (BPO, antibiotics, retinoids.)