Adequate hydration to the skin is essential for skin to maintain its flexibility and plasticity. As discussed above, cells constantly migrate from the bottom layer of the epidermis to the most superficial layer, and finally shed. The enzymes responsible for this shedding (desquamation of corneocytes) are dependent on adequate hydration. When this process is disrupted the skin enters a “dry skin cycle” giving it a rough scaly appearance. Imbalance of the water barrier is characteristic of: conditions like eczema, damage due to ultraviolent radiation, and the aging process.