For washing hands a standard liquid soap was used containing sodium tallowate, sodium cocoate, sodium palm kernelate, aqua, glycerin, paraffinum liquidum, perfume, octyldodecanol, sodium chloride, prunus dulcis, sodium thiosulfate, tetrasodium etidronate, lanolin alcohol, disteardimonium hectorite, linalool, hexyl cinnamal, alpha-isomethyl ionone, coumarin, benzyl salicylate, limonene, butylphenyl, methylpropional, hydroxylisohexyl 3-cyclohexene carboxaldehyde, and CI 77891. Baktolan cream was used in one part of the subjects for treatment of hands and forearms after each hand wash. It contains aqua, mineral oil, petrolatum, paraffinum liquidum, ozokerite, glycerin, glyceryl oleate, lanolin alcohol, microcrytalline wax, montan wax, BHT, ascorbyl palmitate, glyceryl stearate, citric acid, propylene glycol, magensium sulfate, and perfume. It is manufactured by Bode Chemie GmbH & Co., Hamburg, Germany.
Irritant contact dermatitis due to detergents is reflected by scaling, erythema, and edema where the individual morphology depends upon dose, application time, and time of observation . That is why the skin was assessed clinically. In addition, two objective parameter for skin irritation, skin roughness and hydration, were measured at the beginning of the study (baseline value) and at time day 2, 7, 9 and 14 of the study.
The stratum corneum of the forearms was studied. Briefly, a silicon mass was disposed onto each of 12 sequential skin areas of the same size resulting in a cast of skin profile of an area of 12.5 cm2. The silicon masses were assessed with a 3D skin analyzer (Hommelwerke GmbH, Villingen-Schwenningen, Germany). The depth of the skin relief was measured for each sample and expressed as the mean roughness depth (RzDIN), according to the guidelines set in the German Industrial Standards (DIN). The analysis of the casts was restricted to six profile elments per sample, each 4 cm in length, and all sharing a common midpoint. The segments are defined by intervals in which the angle represents 30°. A damaged skin results in a higher RzDIN value [21, 22]. Although the skin imprint technology has in some way limitations in figuring the finest structures of skin surface – because of shape of the tip of the mechanical stylus apparatus operating the imprints – nevertheless, this technology is highly relevant when comparing alterations in skin surface roughness before and after treatment with a cosmetic formula .
The corneometer CM 820 (Courage & Khazaka Eletronic GmbH, Cologne, Germany) was used to measure skin hydration . Measurements were done on the forearm and repeated 5 times for each skin area and time point. The arithmetric mean for each volunteer and time point was calculated. Measurements of skin hydration were accomplished under standardized room temperature uand humidity condtions (21.5°C, 45 RH), according to the recommendations of EEMCO .