Abnormal Epidermal Barrier Recovery in Uninvolved Skin supports the Notion of an Epidermal Pathogenesis of Psoriasis

Psoriasis. Due to primary genetic defects, the epidermal permeability barrier is vulnerable in psoriatic subjects. Mechanical traumas, such as scratches or abrasion, damage the skin barrier, especially during low humidity seasons, such as the winter. While barrier function can be readily maintained in normal subjects, in psoriatic patients, a compromised barrier cannot be completely repaired possibly due to the deficiency of barrier-related proteins resulting from the underlying genetic defect. In addition to higher skin surface pH and lower stratum corneum hydration in winter, defective barrier alone will elevate the pH of the stratum corneum, which in turn, causes