Histological findings in clinically normal palmar skin of patients with psoriasis.

Light microscopy was used to examine the clinically normal palmar skin of 18 psoriatic patients (10 inactive and 8 active) and 18 non-psoriatic control patients. Histological changes in both epidermis and dermis vary with activity of the disease. The findings support the view that defective keratin formation precedes excessive proliferation of epidermal cells.