ABSTRACT
The stratum corneum of affected individuals shows striking features consistent with a hyperproliferative state, as is
indicated by functional studies that measure accelerated epidermal maturation times (2). The physical features accompanying this state are dramatic (4,5). An electron microscopic study of stratum corneum using new fixation methods (11) reveals that dandruff stratum corneum exhibits parakeratotic nuclei, lipid droplets within corneocytes, a decreased number of desmosomes, irregular corneocyte envelope structure, intercellular Malassezia yeasts, and massive quantities of unstructured intercellular lipid (Fig. 29.6). All of these features are consistent with a state in which the feedback between epidermal synthesis and maturation rate is lost and uncontrolled growth leads to corneocytes reaching the surface that are immature and not ready to be shed as individual cells.
