Age, sex, and disease status as determinants of skin hydration and transepidermal water loss among children with and without eczema

Purpose: Skin hydration (SH) and transepidermal water loss (TEWL) are important skin biophysical parameters for assessment of childhood eczema. This study investigated whether age, sex, and disease status influence these parameters. Methods: Skin hydration and TEWL were measured by Delfin MoistureMeterSC and Delfin Vapometer SWL5, respectively, among children aged <= 18 years with and without eczema. Disease status was evaluated using Scoring Atopic Dermatitis (SCORAD) and Nottingham Eczema Severity Score (NESS) clinical tools. Results: Clinical scores and objective measurements were reviewed for 132 patients with eczema and 120 patients without eczema. In both sexes, SH was significantly higher among children aged <= 2 years with and without eczema than among children aged >2 years with and without eczema. Among children aged >2 years, SH was higher among girls with and without eczema than among boys with and without eczema. Regardless of age or sex, SH was lower among children with eczema than among children without eczema. Age-, sex-, and disease-related differences were not observed for TEWL. Skin hydration was negatively correlated with objective SCORAD (r=-0.418, P<0.001), overall SCORAD (r=-0.385, P<0.001), oedema/papulation (r=-0.243, P=0.041), lichenification (r=-0.363, P=0.002), dryness (r=-0.415, P<0.001), and intensity (r=-0.266, P=0.025). Transepidermal water loss was positively correlated with objective SCORAD (r=0.209, P=0.018), overall SCORAD (r=0.215, P=0.015), and lichenification (r=0.240, P=0.043). Skin hydration was negatively correlated with TEWL among children without eczema (r=-0.401, P<0.001), but not among children with eczema. Conclusion: Skin hydration can be used to distinguish clinical differences in eczema based on age, sex, and disease status.