[Shower-bath and its influence on the behaviour of the aerobic resident flora of the human skin. Half-side comparisons between a single shower bath with and without bath supplements (author's transl)].

A method for the in vivo investigation of shower-bath supplements and their influences on the human skin flora is presented. The shower-bath supplement is added in a constant dosis directly to the shower-jet to obtain constant conditions of shower-bathing on the human skin. Different concentrations of the shower-bath supplement in neighboured areas of the skin can be avoided and this allows to make comparative investigations of the effect of shower-bath supplements to the normal human skin flora. The reproducibility of the results and the accuracy of the method were investigated in half-side comparisons of the aerobic resident flora of the flexor sides of the forearms in three groups of volunteers, 60 persons in total. A marketable product in two slightly differing modificatons was used as shower-bath supplement. Half-side comparisons between each of the two supplements against water alone and between the shower-bath supplements directly were performed. The detergent washing method was used for sampling the skin flora. Statistically significant changes of the aerobic resident flora in the half-side comparison between the two supplements were obvious only 24 h after a single bath. It could be proved that the results can be reproduced at different times and with different groups of vlunteers. Further more, that a half-side comparison between th two shower-bath supplements detects more sensible differences in the effect on the human skin flora of the two marketable products than the comparison of each supplement with water alone.