A bioengineering study on the efficacy of a skin protectant lotion in preventing SLS-induced dermatitis

Background/aims: This study evaluated the efficacy of a dimethicone skin pr otectant lotion against sodium lauryl sulfate (SLS)-induced irritant contac t dermatitis (ICD) by clinical visual grading and bioengineering techniques in 12 healthy humans. Methods: The flexor aspects of both forearms of the subjects were used as t est sites. Each test was duplicated to diminish the variations of the test sites. In a random order and a double-blind manner, two test sites were pre treated either with the testing protectant lotion or with its vehicle contr ol prior to contact with SLS. Thirty minutes later, 0.2 mi of 0.5% SLS in a polypropylene chamber was applied to each pretreated site. One additional test site served as a positive control (without lotion), receiving the irri tant only. After 24 h of exposure to the irritant, the chambers were remove d. The efficacy of protective effect was determined by four parameters: vis ual scoring (VS), transepidermal water loss (TEWL), skin color (a* value). and cutaneous blood flow volume (BFV). All test sites were assessed with th e parameters daily for 5 days. Results: The VS data showed a significant decrease on the site pretreated w ith protectant lotion in comparison with the SLS-only treated site (P<0.01) and with the site pretreated with control vehicle (P<0.05) (overall for 5 days). TEWL value was significantly decreased in comparison with the SLS-on ly treated site (P=0.02 at day 2; P=0.008 at day 4; P=0.014 at day 5) and w ith the site pretreated with the control vehicle (P<0.05) (day 2, 4 and 5). However, the BFV and a* values did not show a statistical difference betwe en protectant lotion, vehicle, and SLS-only treated sites. Conclusions: This study demonstrated that appropriate dimethicone skin prot ection products may provide certain benefits from surfactant ICD. The skin protectant lotion may be used to prevent ICD in home or work environments, where skin irritants may induce dermatitis or eczema.