The rate of formation of corneocyte layers after stripping the noninvolved psoriatic skin and its relation to parakeratosis and epidermal enzyme levels.

Corneocyte layer formation rate using dansyl chloride as corneocyte marker was followed in noninvolved skin during a period of 2 weeks after that the skin had been subjected to cellophane stripping. The rate increased after stripping in 7 of 9 tested but it was not paralleled by any apparent parakeratosis. In 1 of 9 patients a Koebner reaction occurred. The corneocyte formation rate in the Koebner reaction was 6.1 times that of the noninvolved skin and with a degree of parakeratosis of 41%. In involved skin, a positive correlation, coefficient 0.81, was shown between corneocyte layer formation rate (range 3.9-15.2 layers/day) and degree of parakeratosis (range 24-100%). In the skin 5 to 14 days after stripping the rate of formation of the corneocyte layer varied from 1.6 to 8.2. In the noninvolved and involved skin the mean rate was 2.2 and 9.7, respectively. In the stripped skin epidermal glucose-6-phosphate dehydrogenase and pyruvate kinase activities generally were the same as those of the noninvolved skin. In the Koebner reacting epidermis the 2 enzymes were increased 2.2 and 1.1 times the noninvolved levels but were statistically not significantly increased from control values.