52 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (10) G. Sauermann, unpublished results. (11) G. Sauermann, H.-J. Dfising, U. Hoppe, M. Klier, and H. W. Kreysel: Betrachtungen fiber qual- itative und quantitative Wirkungen einer W/O-Emulsion, J. Soc. Cosmet. Chem., 33, 263-280 (1982). (12) E. Hecht, Optik (Addison-Wesley, Bonn, 1991). (13) J. R. Lakowicz, Principles of Fluorescence Spectroscopy (Plenum Press, New York), Chapters I and 11. (14) W. A. G. Bruls, H. Slaper, J. C. van der Leun, and L. Berrens, Transmission of human epidermis and stratum corneum as a function of thickness in the ultraviolet and visible wavelengths, Photochem. Photobiol., 40, 485-494 (1984). (15) Publication in preparation.

j. Soc. Cosmet. Chem., 44, 53-63 (January/February 1993) Quantification of dry (xerotic) skin by image analysis of scales removed by adhesive discs (D-Squarnes) HARALD SCHATZ, ALBERT M. KLIGMAN, SCOTT MANNING, and TRACY STOUDEMAYER, University of Pennsylvania School of Medicine, Department of Dermatology, Philadelphia, PA 19104-6142 (H.S., A.M.K.), and Biosearch Inc., 3408-50 "B" Street, Philadelphia, PA 19134 (S.M., T.S.). Received June 28, 1992. Synopsis Clinical grading of dry (xerotic) skin is unreliable, being influenced by several variables, especially ambient humidity. We utilized commercially available adhesive-coated discs (D-Squames) to sample the outer portion of the stratum corneum. A procedure was then developed using image analysis to quantify the degree of scaling, using two parameters: 1) the percentage area covered by scales and 2) the distribution of scales accoMing to five thickness levels. There two values were mathematically integrated into one final value, the desquamation index. We showed that image analysis accurately distinguished the intensity of scaling among individuals whose legs were, respectively, non-dry, moderately dry, and severely dry. The method was especially valuable for quantifying the differing efficacies of three moisturizers evaluated by the regression procedure. INTRODUCTION The subjective assessment of dry xerotic skin by sight and touch is fraught with errors. Grading is strongly influenced by ambient meteorological conditions. For example, in Philadelphia, Pennsylvania, one day of wet, warm weather in winter hydrates the surface and sharply reduces the signs of dry skin, though no real change to the desquamating portion of the horny layer has occurred. The limitations of subjective grading are numerous, well known, and a source of frustration to clinicians and manufacturers of moisturizing products (1). Collecting corneocytes on adhesive tape is one approach toward an objective assessment of scaly, rough, xerotic skin. The stripping technique was first described by Wolf over 50 years ago but has never come into fashion (2). Later, workers in our laboratory utilized adhesive-coated glass slides (sticky slides) to obtain a sample of the loose desquamating portion of the outer horny layer (3,4). When appropriately stained, scales, which are really clumps of corneocytes, develop an intense color. However, the 53