JOURNAL OF COSMETIC SCIENCE 8 related to the glue from the adhesive tape (Micropore®). This hypothesis was based on the location of the irritation being observed under all patched sites under the adhesive tape in the posterior chest area. The second case was a report of mild skin irritation which was thought to be infl uenced by the weather conditions during the study period, as the study was conducted during the summer months. This did not impact the data generated during the study observa- tion period. The data from the three studies described herein, summarizing the dermatological assess- ments of topical compatibility (primary and cumulative irritability and sensitization), photoirritant and topical photosensitizer potential, and acceptability under normal use conditions, support the use of the prototype cosmetic lip balm as a suitable product for use on sensitive skin. ACKNOWLEDGMENTS The author would like to thank Health Interactions, San Francisco, CA, for their medical writing assistance with this article. REFERENCES (1) Z. Ya-Xian, T. Suetake, and H. Tagami, Number of cell layers of the stratum corneum in normal skin– relationship to the anatomical location on the body, age, sex and physical parameters, Arch. Dermatol. Res., 291, 555 (1999). (2) R. J. Rycroft, T. Menné, P. Frosch, and J.-P. Lepoittevin, “International Contact Dermatitis Research Group (ICDRG) Adapted Scale,” in Textbook of Contact Dermatitis, 3rd Ed. (Springer-Verlag, Berlin, 2001), p. 1114. (3) J. Escalas-Taberner, E. González-Guerra, and A. Guerra-Tapiac, Sensitive skin: A complex syndrome. Actas Dermosifi liogr, 102(8), 563–571 (2011). (4) M. A. Farage and H. I. Maibach, “Sensitive skin: New fi ndings yield new insights,” in Textbook of Cosmetic Dermatology, 4th Ed., R. Baran and H. Maibach. Eds. (CRC Press, London, 2010), Chapter 8. (5) H. I. Maibach and F. N. Marzulli, “Chapter 10 Sensitive Skin,” in Dermatotoxicology, 7th Ed. (CRC Press, Boca Raton, Florida, 2007). (6) Z. Draelos, Atlas of Cosmetic Dermatology, 1st Ed. (Churchill Livingstone, New York, 2000). (7) K. J. Frosch, A. M. Kligman. A method for appraising the stinging capacity of topically applied substances, J. Soc. Cosmet. Chem., 28(5), 197–209 (1977). (8) T. B. Fitzpatrick, Soleil et peau (Sun and skin), J. Méd. Esthét., 2, 33–34 (1975) (in French).

J. Cosmet. Sci., 69, 9–17 ( January/February 2018) 9 Evaluation on an Optical Scanning Device for Skin Profi le Measurement JIUAI SUN, School of Medical Imaging, Shanghai University of Medicine and Health Sciences, Shanghai, China, 201318 Accepted for publication August 22, 2017. Synopsis This paper describes experimental evaluations of an optical scanning device for skin surface recovery using multiple light source photometric stereo method. The portable optical device based on the principle of six- light photometric stereo was developed and subjected to evaluation and advancement through clinical trials for the purpose of monitoring skin conditions. As the device can provide objective topographic data for the description of the skin surface condition, the evaluation processes are mainly applied on skin in vitro and in vivo and compared with a commercial product, PRIMOS, which has been so far considered as a standard device used for skin surface measurement. The results of the experiment show that the topography measured by the device is signifi cantly closer to that of the ground truth. Meanwhile, the new optical scanning device demonstrates better performance in measuring skin surface in vivo, superior to that of the PRIMOS. INTRODUCTION SKIN TOPOGRAPHY MEASUREMENT IN VITRO AND IN VIVO As one of the largest organs of human body, it is important to be aware of changes in the condition of the skin surface as an important indicator of human health. However, the skin surface in vivo has proved diffi cult to monitor and record because of its complex char- acteristics. For example, it is complex in structure, elastic in behavior, and easily shrunk or stretched when subjected to extreme changes in the external environment. It is also optically complex in terms of its light transferring properties. As such, few instruments are available to measure such an object accurately (1). Skin replicas were used as a simple and repeatable approach to record the microstructures of the skin without affecting skin function and structure. Essentially a negative skin rep- lica can be easily obtained by smearing a silicon rubber material mixed with a catalyst over the skin surface. This is left for several minutes before being taken off. Fine details in the form of the furrows and peaks of the skin relief can be reproduced exactly when this process is carefully undertaken. After the replica has been produced, measurement of skin Address all correspondence to Jiuai Sun at sunja@sumhs.edu.cn.