Dye exclusion as a means to measure wetness protection of human skin

Background/purpose: Excessive skin hydration from occlusive coverings such as absorbent articles, bandages, etc. has been known to compromise the skin's barrier properties. Damage to the stratum corneum occurs from prolonged exposure to wetness and limited product breathability, which reduces evaporation. Protection from wetness may be imparted by barrier materials, such as lotions and ointments on the skin. Barrier materials are traditionally applied by hand from bulk containers (bottle or tube). In recent years, diapers have been made that contain barrier ointments designed to transfer to the skin during wear. The purpose of this research was to develop a reliable in vivo method for evaluating skin wetness protection when using personal products. Method: The means for evaluating wetness protection in vivo is dye exclusion evaluation on human skin. Dye exclusion involves application of a barrier material, followed by dye application and skin staining evaluation. The dye exclusion method may be conducted on adult forearms with direct application of the barrier material or on infant or adult torsos after wearing a diaper or incontinence product (or other personal products) that contains the barrier material. Dye exclusion on infants used cosmetic dyes (safe for use in the eye area). Results: Dye exclusion demonstrated skin protection on both adult forearms and on infant buttocks. Ointments in diapers protected the skin from the dye when diapers were worn from a few hours to several days (with appropriate changes of product). Conclusions: The dye exclusion method was able to demonstrate the advantage of barrier ointments for wetness protection and also to discriminate between ointment formulations.