[Diurnal dependence of skin reactions in the administration of external substances]

In order to investigate the influence of the application time of the day on skin reactions, test persons were treated with various substances inducing experimental inflammation in human skin. Additional tests provided us with data regarding the antiinflammatory activity of topical glucocorticoids on the experimental inflammation as well as the vasoconstrictive activity dependent on the application time of the day. Although all tests showed great individual scattering ranges, statistical evaluation did not reveal any clear evidence for the supposition that pharmacological responses of the skin may be influenced by the hour of the topical application. Thus, it seems not likely that the success of topical treatment of toxic dermatitis by means of glucocorticoids depends on the hour of application.