I get stiff neck here & there along with pain pain & tenderness on some of my cervical spine. I also get on & off pain that goes into my left shoulder. I also get spasms all around the area now & then. So far it hasnt gone to my right, though. I also have alot of spine problems in my lumbar spine but I am not sure if my neck issues are due to that or if I have a seperate problem in my neck area. Or another seperate problem with my shoulder. I was told, though, that is probably not lupus related. I have other body parts that are more troublesome right now so I've never had me neck area checked out. I thought it was due to my posture before surgery, but I've been getting some problems again after surgery and after my posture's correct.
What I found to help the best were moist heating pads (I bought one specifially designed for the neck and shoulder area and it has strings to tie it in place. Warm it up in the microwave and put it on...it helps to soothe the area alot as long as it's on and still warm. I've also stuck a bunch of the stick on heat pads all over my neck and shoulder for times when the regular heating pad wasn't feasible. I tried ice, but in my case, it made it more painful and spasmodic.
Oh, one other thing I found that helped while sleeping. I use a small buckwheat filled cervical pillow. That made a big difference in teh stiffness, anyway. I can't even sleep without it anymore. Even after my surgery, in my hospital bed..it started hurting me so I rolled up some towels and formed them into a horseshoe shape to lay on. But when the nurse saw me, she was so nice, so went & got me some nice hot towels and made a better one for me.
Perhaps you might want to try some of everyone's suggestions & see if any help at all.