I'm wondering if maybe you have a yeast infection. It is possible to have it in the breasts without having noticed it elsewhere. Yeast thrives on sugary substances, so get yourself checked for this.

Also you might find that using less soap in the shower on your breasts and keeping them moisturized with lotions will help with some of the itchiness. Although we are in spring, we are still in the dry times from winter.

I would invest in a lotion as well. If the skin seems to have scabs, it is probably dry and a bit sensitive. Dry skin is usually really itchy. Moisture from lotion should help a lot.

I know that it's mostly for breastfeeding, but there's no reason why you can't use Lanolin as well on your nipples. Should clear things up really fast.

Hormones can cause itchy breasts. Do you have eczema or psoriasis? These conditions can cause scabbing and itching on the breasts. Topical moisturizers should help. I agree with Mominashoe - try lanolin. Cocoa butter is great too. If the itchiness persists aveeno makes an anti-itch lotion that is very effective. It comes in a lavender scent that is not heavy. A doctor can prescribe a steroidal cream to help with the itch as well.