Influence of differences in washing methods on skin texture

The objective of this study was to clarify the effects of different body washing methods on skin texture.

Subjects were nine healthy women in their 20s. Skin on the inside of the forearms was washed every day for 4 weeks with protective washing (right forearm) and with non-protective washing (left forearm). We performed comparison of the right forearm and the left forearm. For the evaluation of skin texture, the interval of the sulcus cutis, and the mean and variance of the thickness of the sulcus cutis on digitized images were measured. Moreover, the numbers of equilateral triangles consisting of sulcus cutis were counted to evaluate skin texture.

From the first week, the interval of sulcus cutis was significantly narrower with protective washing than with non-protective washing. The numbers of equilateral triangles increased significantly more with protective washing than with non-protective washing in weeks 1, 2 and 4. Although this study found no significant difference in mean of the thickness of the sulcus cutis, the interval of sulcus cutis and the number of triangles differed significantly with protective washing. The narrower intervals between sulcus cutis mean finer-textured skin and sulcus cutis are formed by triangles or quadrilaterals, and the more uniform these shapes are, the finer and more regular the texture Therefore, skin texture may have become finer as a result of protective washing.

These findings suggest that protective washing produces an even skin texture. They also suggest that number of equilateral triangles, as used in this study, may be useful as an index of skin texture.