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.

page 5 of 8

ROIT skin protective evaluation: Schnetz et al. utilized a short-time, repeated occlusive irritation test (ROIT) via a standardized protocol to evaluate skin protective products in two phases—i.e., 12 days and 5 days—in several clinical centers. Skin was treated by the irritants 0.5% SLS and toluene twice daily for 30 min. Inflammation was measured by bioengineering methods (TEWL and colorimetry) and clinical scoring. The 5-day protocol was sufficient to achieve significant results. Furthermore, in spite of the expected inter-center variations due to heterogeneity of the individual threshold of irritation, interpretation of clinical score and inter-instrumental variability, the ranking of the vehicles regarding reduction of the irritant reaction was consistent in all centers.

Oil-containing BC for health care use: McCormick et al. measured the efficacy of a BC and an oil-containing lotion for protecting the hands of health care workers with severe hand irritation. Objective and subjective parameters for scaling, cracking, weeping, bleeding and pain were blindly scored by two investigators weekly for four weeks. Subjects in both groups experienced marked improvement in overall hand condition, particularly in scaling, cracking and pain. Volunteers randomized to use the oil-containing lotion showed the greatest improvement.

LIBS evaluation of BCs: Sun et al. utilized laser-induced breakdown spectroscopy (LIBS) to evaluate the effect of BCs on human skin. Three representatives of commercial BCs promoted as being effective against lipophilic and hydrophilic substances were evaluated by measuring the zinc absorbed through the stratum corneum. Four consecutive SSBs were taken from the biceps of the forearms of six volunteers at 0.5 hr, 3 hr after BC application. The BCs provided appreciable protection against the penetration of both ZnCl2 and ZnO into the skin when compared with control skin (without BC treatment).

Aluminum chlorhydrate skin protection: Perrenoud et al. compared a BC formulated with 5% aluminum chlorhydrate as the active ingredient with its vehicle in 21 apprentice hairdressers, a double-blind crossover study. The efficacy of the creams was evaluated through clinical scores by researchers, biometric measurements and subjective opinions of the subjects. The researchers observed little difference in efficacy between the protective cream and the vehicle. However, aluminium chlorhydrate in the protective cream had a positive effect against work-related irritation.

ICD/ACD protection with o/w cream: De Paepe et al. investigated the effects of an o/w cream on barrier function in experimentally elicited ICD and ACD in 24 white female volunteers. In the ICD study, 1.25% SLS patches were applied to the forearms of volunteers, followed by twice daily application of the cream for 14 days. Researchers observed significantly improved TEWL in SLS-damaged skin, leading to a complete recovery on day 15, compared with the untreated site.