Water protective effect of barrier creams and moisturizing creams: a new in vivo test method.

Frequent exposure to water is an important risk factor for the development of irritant hand eczema. Evaluation of cream efficacy in protecting against water is difficult. A new non-irritant, non-invasive method is introduced, based on evaluation of colour intensities when an aqueous solution of crystal violet is applied to the skin, after pretreatment with different creams. By skin reflectance measurement, differences in colour intensity were objectified. Measurements of transepidermal water loss were also performed, 2 barrier creams and a moisturizer were tested on the dorsal and volar aspects of the hands. One barrier cream contained silicone, the other solid particles. The moisturizer had a high content of lipid. In one experiment, the immediate effect of the creams in protecting against water was evaluated. In a second experiment, the water resistancy of the creams was tested, using a standardized water immersion procedure (4 x 20 min). The barrier cream with particles gave the best immediate protection (dorsal 76%, volar 69%). The moisturizer was intermediately protective (dorsal 57%, volar 34%), while very little protection was found for the silicone-containing cream (dorsal 16%, volar 10%). The water immersion procedure resulted in only minor changes in protection for each cream. When comparing transepidermal water loss in the treated areas with pretreatment values, a reduction was recorded only for the particle-containing barrier cream. The colour method described may be used as a quick and easy test of the protective effect of creams against water.