My sfn started with sunburn feeling all over my entire body. If you scratched my skin, it would burn badly like I was sunburned.

This waxed and waned for a few months, and I started getting pin prick sensations everywhere-like someone was poking me with a needle.

The burning eventually stopped for the most part this past winter. Now I get some tingling, lots more pinprick sensations (like tiny bees stinging you), cramping, twitching, and compression pain. I have also lost some sensation on the backs of my calves and areas of my scalp...but even if I scratch other areas it'll still feel slightly weird-so I think I have probably lost some sensation all over.

My is obviously not length dependent, as it started all over my body. My feet and hands actually have all their sensation still I think.