Cleansing‐induced changes in skin measured by in vivo confocal raman spectroscopy

BACKGROUND: One of the most important steps people can take in reducing the spread of bacteria and viruses is washing the hands with soap and water. Frequent washing, required in certain occupations, can lead to skin dryness, chapping, and itching. MATERIALS AND METHODS: In vivo confocal Raman spectroscopy was used to study short-term effects of hand washing on product deposition, lipid acyl chain structural disordering, and extraction of important skin components such as natural moisturizing factors, cholesterol, ceramides, amino acids, and changes in skin hydration. Effects of use of either soap, synthetic detergent, or triethanolamine (TEA)-soap/ glycerin were compared at two water temperatures. RESULTS: Soap use resulted in significant deposition at all depths to 20 mum at 25 degrees C and at the surface and 2 mum at 37 degrees C. Significant decreases were observed in relative amounts of all skin components studied. NMF levels were not changed. Skin dehydration was observed for use of soap at 37 degrees C. CONCLUSIONS: Short-term effects of frequent hand washing can be monitored with in vivo confocal Raman spectroscopy. Effects of frequent washing may be reduced with lower wash temperature and products. Skin dehydration is not associated with lipid chain disordering.