Electron microscopy studies on dermal nerves in psoriatic plaques.

A morphological study on the ultrastructure of cutaneous nerves has been carried out on 5 patients with florid psoriasis. With the electron microscope we compared nerves in the dermis from psoriatic plaques, clinically normal looking skin from psoriatics, and skin from healthy people. No qualitative difference could be found in any of these three groups. Nor did the quantitative study show any difference in the ratio of myelinated to unmyelinated axons, or in the distribution of the fibre diameter of both sorts, or in the degree of myelination. As concerns possible qualitative changes in psoriatic plaques after treatment and subsequent recovery, we have not observed any change in the small myelinated dermal nerves.