As part of an auti immune condition that I have my hands often go completely white and numb. This year it has been gradually getting worse and over the past few months I have had 6-8 hours a day when I can't feel any of my fingers (not ideal when you sew for a living!).
On Sunday I was weeding in the polytunnel and ended up with stung hands from all the tiny nettles in the salad beds.
And my hands weren't numb on Monday or Tuesday either.
I woke up with numb fingers this morning which had spread to the rest of my hands by 9.30 - so I went in search of some nettles (not hard to find in our garden) and deliberately stung one of my hands. Within quarter of an hour that hand was back to normal and within half an hour both were working fine.
Obviously I will have to keep experimenting - it may be co-incidence - but I thought that I would put it out there as so many people get the same thing and nettle stings are much, much better than numb hands. . .