Try this:
Using Word Find & Replace:
Check the 'Use Wildcards' box
In the Find box, type
In the Replace box, type
then [Ctrl]-I or Format - Font - Italic to specify Italics
Then press the 'Replace All' button
Attached is a screencap of the Find/Replace box in Word so you can see what it should look like.
Caveat: My version of Word is pretty old. The box may have changed.