A model to assess the efficacy of moisturizers--the quantification of soap-induced xerosis by image analysis of adhesive-coated discs (D-Squames).

Clinical grading of dry skin syndromes (xerosis) is beset by many variables which limit its reliability. Removing scales onto adhesive coated discs (D-Squames) has provided a means for objective measurement of xerotic states. Using image analysis we have modified the basic procedure to assure greater accuracy and reproducibility. The distribution of grey values on the discs was determined, from which a single value of the degree of scaling was calculated. We term this the scaling index. To induce xerosis, the lower legs of 22 women, aged 26-64, were washed daily for 10 days with soap. After washing, one side received a moisturizing lotion, the other served as an untreated control. At specified intervals, scaling was graded clinically, electrical conductance was measured and D-Squames were obtained. On the moisturizer-treated legs there was a significant decrease in dryness grades and scaling indices at all time points. Conductance was significantly increased on days 8 and 11. The untreated washed legs showed no changes in clinical grades, although conductance significantly decreased and the scaling indices increased in the last stage of the study. D-Squame analysis unequivocally revealed the beneficial effect of a moisturizer on soap-induced xerosis and the expected increase in scaliness without treatment.