Neurohistological Changes in Prurigo Nodularis

The innervation of a nodule from a patient with prurigo nodularis was studied using the improved silver impregnation technique of Richardson (1960). Profound changes were seen in nerve fibers, where there was a very marked acceleration in the rate of "turnover," and in Schwann cells, where there was hyperplasia and schwannoma formation. A possible peripheral neural relationship was noted between prurigo nodularis and lichen simplex chronicus.