Some Observations on Dandruff

Abstract

Synopsis--Dandruff and nondandruff subjects were compared with regard to a number of variables. Histologically, the major differences between the dandruff and nondandruff speci-mens were in the horny layer. Normally, the scalp horny layer consists of 25-35 fully kera-tinized, closely coherent cells arranged in an orderly pattern. In dandruff, the intact horny layer usually has fewer than 10 cells, parakeratotic cells are common, and the pattern is dis-ordered. Unlike the nondandruff horny layer, crevices occur deep within the dandruff stra-tum corncure, resulting in "cracking up " into large flakes. The permeability of the dan-druff horny layer is increased. This reflects not only the reduced number of coherent cells which can function as a barrier, but increased porosity derived from the "cracking up " of the horny layer. The composition of the microflora is the same in dandruff as in nondandruff, consisting principally of Staphylococcus epidermidis, Corynebacterium aches and Pityrosporon species. However, there is a great numerical increase in the aerobic and fungal flora of dan-druff, roughly proportional to the quantity of scaling. Certain antibacterial and antifungal agents effected a great decrease in the microflora without eliminating dandruff. Various methods of studying epiderxnal kinetics indicate that the epidermal turnover time is de-creased in dandruff, i.e., epidermopoiesis is accelerated. It is proposed that dandruff represents a basic change in the rate regulating mechanisms of cornification. Accelerated epidermopoiesis leads to imperfect keratinization and faulty "cracking up " of the horny layer.