Is the stratum corneum of uninvolved psoriatic skin abnormal?

A variety of abnormalities of the uninvolved skin have been reported in psoriasis, but there are few studies in which abnormalities of the stratum corneum (SC) have been investigated. In this study we have examined the intracorneal cohesion and structural detail of corneocytes of the SC from involved and uninvolved sites in 24 patients with psoriasis and 10 controls. We have found that intracorneal cohesion is increased in the involved and uninvolved skin of psoriatic patients compared to controls and that there are abnormalities of stratum corneum and corneocyte structure as determined by scanning electron microscopy. The changes in the uninvolved sites may well be due to the increased rate of epidermal cell production in these areas.