What is lichen simplex chronicus?

Lichen simplex chronicus (LSC) is not a disease but rather a reaction of the skin to chronic friction from rubbing or scratching. LSC may be superimposed upon normal skin, but it is often a secondary condition of chronically inflamed skin. The clinical appearance, termed lichenification, is characteristic, regardless of the underlying etiology. Relative thickening of the skin, with accentuation of the normal skin lines, is typical. Closely set lichenoid papules may be discerned at the periphery. Frequently, the lichenified plaque maintains a dusky violaceous hue.