I recommend you read this page in all its sections.
It is interesting to note that many symptoms of pssd and pfs could be included in this picture, both those of numbness and those of pain, up to forms of dysautonomia.
The peripheral neuropathies of the small fibers can have very different symptoms depending on where they strike, they are little known, little recognized, not treatable.
Those who have this problem often and for a long time without a diagnosis, are told that they are psychiatric problems.
Classical neurological examinations such as electromyography do not show the neuropathies of small fibers, but more specific and difficult to obtain examinations are needed.
Recent studies have shown probable link with sodium channels and probable autoimmune causes.
(apologize if repeating the subjects)