[cypher]

Keep an eye on the itching & scratching, if it carries on it could be either that she's reacting to something, substrate or food possibly, or she could have a mite problem which would need to be treated by your vet.
Have you changed anything in the cage recently that might be causing her a problem?
The patch of fur on her back sounds as though she may have been rubbing against something, have a check around the cage & watch to see if there is anything she could be rubbing against, also it could be the wheel if it's not big enough for her.