hey sista!! i'm transitioning so don't know how much help this will be to you. there's also a real old post (in LHCF terms haha) that asks a question similar to: how long is your nape? i posted there about my problem too.
http://www.longhaircareforum.com/showthread.php?t=104859&highlight=long+nape.
maybe there's some info there that can help also.
i believe that my nape area had been damaged by overprocessing that area when relaxing. that relaxer box always says to do the nape area first and that's exactly what i used to do. it held the chemical the longest and it's extremely difficult if not impossible not to get that stuff on your skin in this area.
when i read this post i couldn't help but think about myself and my nape issues and i ran to grab my camera and take some quick pics.
what worked for me: well, i chopped that area a few months ago then babied the heck out of it. during the summer i mostly kept it in 4 mini braids loaded with moisturizers and oils. it was hidden under the rest of my hair so no one was the wiser cept for me and my nape.
i believe i had/have scab hair since there's no other explanation for how difficult it has been to grow out.
here's a pic of what still needs working on:
http://public.fotki.com/IsItOnlyHair/textureshair-typing-/my-nape-aka-the-pro/img0428a.html
here's a pic of the rest - it's looking pretty normal now.
http://public.fotki.com/IsItOnlyHair/textureshair-typing-/my-nape-aka-the-pro/img0430a.html
(that left side is proving to be very much of a challenge but we'll get the problem licked sure nuff).
perhaps you can try that method, someone here mentioned that's what they did/were doing and it really worked miracles for me.