ABSTRACT Background Glove occlusion increases skin susceptibility to irritants (‘occlusion effect’). Previous experimental data showed that applying protective creams (PCs) before glove occlusion does not prevent this effect and may even aggravate irritant responses. Objectives To assess whether the application of PCs after glove occlusion modifies the occlusion effect. Methods In a randomized, single‐blind (participants were blinded) study, 68 healthy volunteers were examined over 10 days. Two commercially available PCs (A, B) and one standardized model cream (C) were applied after occlusion for over 4 h to defined forearm sites. On day 8, sites were exposed to 0.5% sodium lauryl sulphate (SLS) for 24 h to evaluate skin irritation susceptibility. Additional conditions included (I) daily application of cream C without occlusion until day 7 or (II) until Day 8, with the final application 10 min before SLS exposure. Skin responses were assessed by TEWL, corneometry, colourimetry and clinical scoring. Wilcoxon signed‐rank tests were used to compare control areas to sides after PC application. Results Post‐occlusion application of the PCs did not demonstrate a consistent protective effect. Cream A slightly reduced SLS‐induced TEWL (10.88 g/m 2 /h after application following glove use vs. 12.13 g/m 2 /h without application; adjusted p > 0.05), whereas cream B increased TEWL (13.44 vs. 12.42 g/m 2 /h; adjusted p > 0.05). Cream C showed no significant effect on TEWL (11.99 vs. 12.38 g/m 2 /h; p > 0.05). In contrast, application of cream C shortly before SLS exposure in the absence of occlusion (condition II) significantly reduced TEWL (7.09 vs. 12.38 g/m 2 /h; adjusted p < 0.0001) and erythema. However, earlier application (condition I) did not yield a protective effect (11.92 vs. 12.38 g/m 2 /h). Conclusions In the majority of study scenarios, application of PCs after glove occlusion did not have a clinically relevant positive effect on the skin responses studied. Protective efficacy probably depends on formulation and timing, underscoring the need for evidence‐based recommendations.
Gina et al. (Wed,) studied this question.