Rekordbox and Itunes - syncing playlists

Hi,
I am using Rekordbox but organise all my music in iTunes and I have a lot of playlists.
I'm wondering what is the best way to go about syncing Rekordbox with my iTunes playlists.

For example, say I have 20 playlists on iTunes for different genres and have imported them to Rekordbox.
I then add a few songs to each playlist, or maybe just to a few playlists.
What is the cleanest, most efficient way to import all these new songs and update the playlists in Rekordbox?
Do I have to find the new songs in each itunes playlist and drag them to the Rekordbox playlist?
Or do I have to delete all the playlists from Rekordbox box and re-import them?

It would be great if there was a way for these to update dynamically, but I don't think this is possible, so I'm just wanting to know the best way to go about this.

Thanks in advance, Jake