Kinetics of Hyperplasia in Psoriasis

Abstract

Adequate biologic definition of certain disease processes and the morphogenesis of lesions would seem to hold the advantage of giving a kind of understanding on which to base further explorations into the disease under concern. To date there seems to be general agreement that the epidermal lesion of psoriasis can be categorized by hyperplasia and increased mitotic activity of the epidermis. This limited definition does not specifically identify psoriasis, for it is also applicable to a number of unrelated epidermal lesions on which there is also but casual information. This study attempts to characterize the hyperplasia of the epidermis in psoriasis, and to outline the kinetics of some of the changes in the tissues and cell populations involved. Materials and Methods For the analyses described below, biopsy specimens of psoriasis lesions were obtained from the upper back of six patients (four men, two women) with psoriasis vulgaris; from four of