try and keep then hydrated - i just wacked biooil on mine but if they are already sentative i'd say go for more of a barrier cream. maybe get some nipple cream (lanosh I think its called) also make sure your bra fits well, I know how itchy I get when I have loose fabric rubbing against me, and if its too tight it can rub and cause itchyness.
most importantly dont scratch! lol easier said than done i know! you can press, poke, pinch, but defo no nails