--is unequivocally positive even in people with symptoms of small-fiber neuropathy.

A lot has to do with the extent of the damage, and exactly from where the samples are taken. Damage can be patchy, or the "normal" figures given for intraepidermal nerve fiber density--anything withing the fifth to ninety-fifth percentiles--may technically be designated as normal, but not be normal for you (it's almost impossible to know at what level one started before symptoms).

Do you have the report yourself, to relate to us?

Also, while skin biopsy is the gold standard for small fiber syndromes, there are some other (older) tests that are sometimes used, such as qualitative sensory testing and certain autonomic tests, such as quantitative sudomotor axon reflex testing (QSART), which measures the sweat response of small skin fibers.

There are certainly other conditions that can mimic small-fiber symptoms--circulatory dysfunction and central nervous system problems (such as central nervous system demyelinating syndromes) among them--what other testing has there been for these?