Cumulative effect of surfactants on cutaneous horny layers: adsorption onto human keratin layers in vivo.

An attempt has been made to determine the adsorption ability of surfactants by the human horny layers in vivo. For this purpose, a technique utilizing an acidic dye such as indigo carmine was applicable and convenient. Our in vivo study estimating adsorbing residual amounts of surfactants has revealed that there is a positive correlation between adsorbing and roughening effects. It is suggested that the pathogenesis of hand roughness is primarily related to the cumulative injury of the stratum corenum by adsorbing residual surfactant molecules.