A Review of Anti-Irritants, Part I: Barrier Cream Efficacy on Contact Dermatitis*

By: Howard I. Maibach, MD, University of California School of Medicine; and Hongbo Zhai, MD, University of California

Posted: March 2, 2011, from the March 2011 issue of Cosmetics & Toiletries.

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Preventing glove-induced ICD: Zhai et al. evaluated the ability of a model lipid emulsion to protect against glove-induced ICD. The test emulsion was applied to one hand while the opposite hand remained untreated. After 30 min, both hands were gloved for 3 hr. Skin conditions were evaluated by visual scoring, water sorption-desorption test, TEWL measurement and skin capacitance. This procedure was repeated for five days. Emulsion-treated hands showed significantly greater water holding capacity and lower TEWL values than untreated hands. Researchers concluded that the test emulsion minimized glove-induced ICD.

Dexpanthenol skin protection: Biro et al. investigated the efficacy of dexpanthenol to protect against irritation in a randomized, prospective, double-blind, placebo-controlled study. Twenty-five healthy volunteers were treated on the inner aspect of both forearms with a formulation containing 5% dexpanthenol or a placebo twice daily for 26 days. From days 15 to 22, 2% SLS was applied to these areas twice daily. Assessments included sebumetry, corneometry, pH value and clinical appearance (photographs). Researchers concluded that dexpanthenol exhibits protective effects against skin irritation.

Evaluating irritancy potential and efficacy: Diepgen et al. compared six commercially available skin care products with two standard experimental designs: the chamber scarification test to assess irritancy potential, and the ROIT, which was developed to evaluate the efficacy of skin care creams. Results showed that a high score in the chamber scarification test for skin irritation was not necessarily correlated to the products’ ability to impede SLS-induced irritant skin reactions. Three products exhibited low irritancy potential and were capable of reducing skin barrier damage induced by SLS while one product showed both irritant potential on scarified skin and also a modest capability to reduce skin irritation induced by SLS.

In vivo ROIT evaluation: Zur Muhlen et al. assessed the efficacy of three products through an in vivo ROIT method. The researchers demonstrated that a multiple emulsion provided the best protection against sodium dodecyl sulphate (SDS). They believed the multiple emulsion increased the content of skin lipids, which reduced the irritation induction or cell death caused by SDS.

Tape stripping protective evaluation: Teichmann et al. investigated the protective effectiveness of one commercially available BC, beeswax and white petrolatumd in six healthy volunteers. The researchers assessed the penetration behavior of Patent Blue V in water on the BC-pretreated skin, in comparison with an untreated site, by tape stripping. The commercial BC did not demonstrate a protective function (e.g., similar to the untreated site), while beeswax and white petrolatum were significant in their efficacy to protect barrier function.