Lidocaine OTC...lidocaine finger test for SFN:
 

This link has a discussion of the new Aspercreme with 4% lidocaine that just came out:

http://neurotalk.psychcentral.com/thread225542.html

and this link has discussion of the test you can do yourself with lidocaine to see if you are positive for SFN.

http://neurotalk.psychcentral.com/thread225598.html
thanks to madisongrrl for this interesting helpful thread.

I took the test!
 

Last night I smeared a liberal amount of 4% lidocaine on the index, middle and ring fingertips of my right hand. Since my fingertips are often wrinkled I looked at them before I started so I could note any changes. I waited 1/2 an hour and removed the creme. According to the chart I was a level 3 which would mean normal reaction. However before the test I was about a level 2 so I'm not sure what to think.

I found this article today that explains why our fingers get pruney in the bath and the relationship to the nervous system. I'm including the link in case you're interested. It seems they knew about this connection in 1930.

http://dujs.dartmouth.edu/news/why-d...y#.VfwwBFL3bCQ