To study the effect of acute infrared radiation-induced alterations in human skin at cellular and molecular level using in vivo confocal Raman spectroscopy.

An increase in the Raman peaks of stratum corneum lipids, decrease in stratum basal DNA peaks, and a shift in the amide I peak of collagen in the skin dermis were observed. One-way ANOVA results showed significant differences among timestamps of stratum corneum, stratum basale, and dermis at all wavenumbers under test (P < .001). Furthermore, paired timestamps also showed significant differences (P < .016) except at two wavenumbers 1293 cm-1 and 852 cm-1 in stratum corneum and basale layer clusters on timestamps (T0 & T30 and T30 & T60, P > .016). This study proved that confocal Raman spectroscopy is an useful technique for early evaluation of IR-induced skin changes.