Lichen simplex: morphodynamic correlates*

Abstract

The rate of epidermal cell proliferation has been examined by autoradiographic methods in lichen simplex chronicus in sixteen patients. The corrected labelling index was found to be 25.9% in eleven biopsies removed 50 min to I h after intracutaneous injection of tritiated thymidine (i.e. similar to that in psoriasis). Twelve biopsies were removed 1–8 days subsequent to injection with tritiated thymidine, and in the autoradiographs that resulted it was found that the rate of travel of labelled cells was not fast as in psoriasis. The possible explanations for the finding of a labeling index similar to that of psoriasis but a slower transit time include; the presence of a greater epidermal volume in lichen simplex; the inclusion of‘high level labelled cells’in the labelling index; and epidermal damage from the trauma of scratching resulting in intra‐epidermal cell death of labelled cells.