Cutaneous xerosis is frequent in uremic patients, but its pathogenesis
is still obscure. In this paper 140 uremic patients under regular dia
lysis have been investigated and followed for a period of 72 months to
look for skin scaling and xerosis. 71 patients had ichthyosiform derm
atosis. This were associated to follicular keratosis in all patients a
nd in 28 of them there was also some degree of plantar keratosis. Ligh
t microscopy examination revealed a thickened, orthokeratotic stratum
corneum and thin granular layer. On transmission electron microscopy d
esmosomal disks were retained up to the superficial part of the stratu
m corneum, and keratinosomes were increased at the margin of the horny
layer and most of them lacked the typical lamelled inner structure an
d appeared vesicular. Moreover in several areas the showed an abnormal
aggregation with the formation of cluster and small chains beneath th
e corneocytes. These findings would suggest that the so-called xerosis
of uremia is a disorder of keratinization caused by a defect in the i
nduction of desquamation.