Quantifying the Relationship Between Skin Temperature and Skin Hydration Measured by Corneometry

Abstract

The role of the skin in forensic medicine is increasingly recognised, particularly in post mortem interval (PMI) determination through its electrical properties. This study investigates the relationship between stratum corneum hydration (SCH), measured by corneometry, and skin temperature (ST), as literature strongly suggests that variations in skin temperature can influence its electrical properties. Twenty-four (24) adult subjects with known cause of death and characteristics were selected and briefly removed from their mortuary cell. ST (°C) and SCH (a.u.) were measured immediately and then at 5-minute intervals for 20 minutes using the Skin-Thermometer ST 500® and Corneometer CM-825® (Courage & Khazaka electronic GmbH, Cologne, Germany) at 3 body sites (cheekbone, abdomen and index finger). The results show a significant inverse relationship between ST and SCH, with a unit decrease in SCH for each unit increase in ST (-1.21 ± 0.55, p=0.028). This relationship was site-dependent (p <0.0001) but not influenced by time since removal from the mortuary cell (RMCT) (p = 0.15), sex (p = 0.39) or PMI (p = 0.88). The results highlight the need for careful consideration of skin temperature when assessing skin hydration, in order to accurately interpret post mortem changes in skin electrical properties, particularly when determining the post mortem interval (PMI).