Direct comparison of skin physiology in children and adults with bioengineering methods

The aim of the study was to investigate whether the physiologic skin parameters of transepidermal water loss (TEWL), stratum corneum hydration (capacitance and conductance), dynamic stratum corneum hydration parameters (hygroscopicity and water-holding capacity), skin color (a* and L* axes; chromameter), cutaneous blood perfusion [laser Doppler flowmetry (LDF)], and pH value differ between a sample of 44 children [C] (average age 3.5 years) and a directly comparable sample of 44 adults (their parents) [P] (average age 34.6 years). The results can be described as follows: TEWL C: 6.2 g/m2/h, P: 5.4 g/m2/h; stratum corneum hydration, capacitance C: 75.4 AU, P: 76.1 AU; conductance C: 27.1 microS, P: 19.2 microS; hygroscopicity C: 129.0 AU, P: 132.7 AU; water-holding capacity: C: 127.7 AU, P: 127.6 AU; redness (a*) C: 7.31, P: 8.21; lightness (L*) C: 67.63, P: 66.36; LDF (%) C: 24.6, P: 18.7; pH value C: 4.91, P: 5.07. In comparison to the skin of the adult sample we investigated (the parents of the 44 children), the skin of the small child can be characterized in the following way: it has a significantly lower hygroscopicity, a lighter (higher L* values) and less red color (lower a* values), and an increased cutaneous blood perfusion (LDF).