Scanning electron microscopic study of dermatoglyphics in carpal tunnel syndrome

The dermatoglyphics of
the volar tip of the thumb and
index finger of 20 patients in the
first stage of carpal tunnel syndrome
(CTS) without electromyographically
detectable thenar
impairment were examined by
scanning electron microscopy with
the aim of analysing its threedimensional
features. In comparison
with 20 healthy controls, only
the central portion of the thumb
and the central, medial and lateral
portions of the index finger
showed clear modifications. A low
grade of hydrosis, confirmed by
morphometrical measurements,
was present in all pathological
samples. Even the dermal ridges
differed from the controls: in the
pathological digits these were less
flattened, more elevated and
decreased in length, and the dermatoglyphics
were less evident.
The keratinocytes were identified
on the dermal ridges in groups of
4–5 elements, with abundant exfoliation
and numerous sweat pores
which were irregular in size but
had an increased diameter, probably
due to compression of the
autonomic fibers contained in the
median nerve. To sum up, by
using scanning electron
microscopy, this study documented
dermal alterations that occur in
the thumb and index finger during
the initial stages of CTS and that
may be features of autonomic neuropathy.