my SFN is related to toxins. It is more or less stable, but as having differant kinds of impaired sensation - it is really difficult to say. One day - is is seems that everything is gone but the other day - burning all over. Not taking any meds, but supplaments as recommanded here and hope for good.
As we aged - we get many other things that confused and change the picture and sometime it is very difficult to point what is the cause.
(remember - English is not my lenguage...)
SFN is rare - but according to my neuro - there are more people with SFN - but the are not DX. I believe him. I know what I did during the last 5 years in order to be DX and didn't get "it is in your head" as an DX.