A particular playlist on iPhone is shown on iPhone but won't appear in iTunes under devices.

While in iTunes, I tried to drag the playlist that I created under devices to All Playlists. Now when I plug my iPhone into my laptop, the playlist does NOT appear under devices in iTunes anymore; however, the playlist is still on my iPhone. I'm afraid that the playlist on my iPhone will disappear if I hit sync since it no longer appears under devices in iTunes. What should I do to keep my playlist that is currently on my iPhone and also get it to reappear under devices in iTunes when I plug my iPhone into my laptop?