Start with soaking that hand in the sink. You can get a plastic dish pan at walmart or a smallish plastic storage container. ($3).
When I was on vacation I made a saturated solution in a pan,
and soaked a cloth in it, and put that on my knee (at the time).
It has to be renewed every 15 minutes or so.
You can also get topical magnesium lotions and liquids you can rub on now. I use a lotion from CVS (I bought 3 bottles) but they are discontinuing it due to lack of consumer interest.
Here are some types of topical forms:
The body lotion is what is best I think. This is available on the net at Amazon and other places at discounted prices.
There is also Kirkman's cream:
I had a patient just before I retired, with scleroderma. Her hands were turning black, and none of the drugs or doctors' treatments worked. I was counseling her on her new medication from a specialist in Texas, and mentioned the epsom salts.... she started and within a week her hands returned to normal color! She then started oral supplements too.
What happens is that magnesium cannot get into the hands and feet from the blood because the vessels clamp down with inflammatory processes. This causes more spasms of the blood vessels and then the tissues suffer. Open them up with magnesium and the blood flows better bringing in nutrients and taking by products of oxidation away. Magnesium also blocks NMDA pain receptors which may be over firing causing more pain.
It would be a good idea to avoid MSG... in foods. This activates that NMDA pain receptor and can make nerve pain worse.
I have a magnesium thread here:
And magnesium is a topic we discuss often at our Peripheral Neuropathy forum here.
This is inexpensive and very effective for many people. So do consider trying it.