Sleep deprivation=sore fingertips. What's going on??

[buttercup]

Ever since I was a kid, if I am severely sleep deprived, I end up with very sore, sensitive fingertips. My fingers look normal, it's more uncomfortable than painful, and it doesn't go away until I have slept well.

I recently started asking my friends and family if they ever experienced this, and the only person who did was my younger sister. This is very odd and I am now fixated on figuring out what it is. Any ideas?

Thanks!