What Causes An Itchy Mole On The Back?

Im a 28 yo male in good health, I have a dime-sized, cauliflower-like mole on my back. I have had it inspected by my physician in the past and it was deemed "normal". Recently it has become crusty and very itchy and it is starting to concern me because of the recent symptoms. I have also recently noticied a small (pencil eraser sized) brown patch on my back a dark brown/black dot inside of it - this one doesn't itch or anything. Should i be concerned?