Measurement of intracorneal cohesion in man using in vivo techniques

Measurement of intracorneal cohesion in vivo should provide quantitative information concerning the process of esquamation. In this investigation three techniques have been employed to measure the internal binding forces within the stratum corneum in vivo. The first technique, cohesography, directly measures the force required to remove stratum corneum of partial thickness from a known area of skin. Sex and site differences were detected using this method. A second technique employs a surfometer to measure the surface contours of the internal face of skin surface biopsies. Quantitative assessment of surfometer tracings reflects both internal structure of stratum corneum and its cohesive property. Positive correlations were found using these two techniques on the forearms of 16 normal subjects. A scrub technique has also been used which can deliver a controllable and measurable stimulus to the skin surface to release corneocytes. Counting the number of corneocytes released provides a further measure of internal cohesion of the stratum corneum but the results did not correlate with the other two techniques. It is suggested that the use of all three techniques might provide a profile of the cohesive property of the stratum corneum.