Remove all Direct Formatting EXCEPT Italics


I have a 500 page Writer document and I need to remove all of the direct formatting EXCEPT the italics. Is there a way to do this automatically? There are italicized words on almost every page which need to be retained and having to go back and reformat them after globally clearing all of the direct formatting is proving to be very, very time consuming.

The original document is in Word format, if that makes any difference.