Superimposed linear psoriasis: a historical case revisited.

In 1978, a case of "ichthyosis vulgaris and ILVEN syndrome (inflammatory linear verrucous epidermal nevus)" was presented by Johannes Ring, of Munich [1]. Based on present knowledge, a diagnosis of superimposed linear psoriasis appears simpler and more appropriate because the 10-year-old girl also had multiple psoriatic plaques, with a symmetrical and non-segmental distribution. The linear manifestation most likely reflects the clonal outgrowth of a population of cells harboring a postzygotic mutation that increased the predisposition to psoriasis.