--there may be both inflammatory and non-inflammatory etiologies that may or may not show "standard" inflammatory markers. Particularly if there is an autoimmune attack by antibodies specific to antigens on small fiber nerve, this may not show up on the usual inflammatory tests as there may not be the same kind of lymphocytic infiltrates usually associated with measures of inflammatory markers (the damage may be caused by antibodies not only hard to measure but very specific to the individual).

Still, in many small fiber syndromes now designated "idiopathic", autoimmune processes are suspected. These may just be as of yet unPROVEN. It is important to note that most of the antibodies to specific peripheral nerve antigens--the type Dr. Norman Latov listed in his Quest diagnostic advisory paper--have only been discovered/recognized over the last thirty years or so.