In healthy skin, there is a normal physiological balance between the production of new cells and the shedding of the old ones. The outmost layer of skin, the stratum corneum, is approximately 20 layers of non-living, yet functional, cells called corneocytes. They are held together by protein bridges called desmosomes. Desquamation is the process by which these protein bridges are enzymatically dissolved allowing the shedding of the most superficial cells. The enzymes responsible for dissolving these bridges can only function in a well hydrated environment.