A comparison of the effects of bath additives on the barrier function of skin in normal volunteer subjects

BACKGROUND: Emollients form an occlusive layer on the skin surface, reducing transepidermal water loss (TEWL), thus providing a temporary restoration of barrier function in compromised skin. This study evaluated the ability of three bath additives to reduce TEWL from compromised skin. METHODS: The stratum corneum on areas of forearm skin was removed by the repeated application of D-Squame discs. After I hour, baseline measurements (t = 0) of TEWL were recorded before each arm was immersed for 10 min in a warm waterbath containing one of four treatments. The arms were air-dried for 20 min and the TEWL measurements repeated. Three further TEWL measurements were made at 30min intervals. Measurements were made using a Tewameter in a controlled atmosphere. RESULTS: There was little difference between the products in terms of changes in mean TEWL values. However, when expressed relative to t = 0 values, some differences became apparent. The mean values for sites treated with Balmandol were lower than the other sites at 60, 90 and 120 min. When analysed by using the summary statistic AUC (area under the curve), the difference between Balmandol(R) and water and also Balmandol and Eucerin(R) was statistically significant (p < 0.05). CONCLUSION: These results would suggest that Balmandol has a greater effect on barrier function (as assessed by measurement of a reduction in TEWL values) than Eucerin.