Wy does my breast itch insIde and can rub it underneath to my rib n o rash with apperance of moles?

Fungal. Could be just skin irritation from sweat, or the beginning stages of a fungal infection. Keep the area dry. If no better, and you're worried, see your primary care doctor for a proper evaluation. Hope this helps!
Breast itch? Not really understanding your question. Best to seek in person MD evaluation...