7-9.Hyperkeratosis and parakeratosis
	Keratinization (metabolism) of a normal outer skin will be performed in a cycle of 28 days. However, it may sometimes be behind or may be rash. By the abnormalities of keratinization, all cause the fall holding the moisture of the skin of power. As for the abnormalities of Keratinization, it is possible to make it recover by the right care by cosmetics.
	Hyperkeratosis （A Keratinization cycle is overdue.） ●Stratum corneum is excessively made, and the state that remains adhering without corneum cell's in the upper layer peeling off and falling is said. The skin partially becomes hard from disorder, and the difference of the height of the skin hill and the skin ditch increases at the cycle of keratinization. Therefore, it becomes a rough skin.	Parakeratosis （A Keratinization cycle is rash.） ●If stratum corneum becomes thin suddenly, keratinization days will be shortened and a skin cell will serve as corneum cell with incomplete having had a core. Since various functions are incomplete corneum cell, barrier ability also falls. parakeratosis may happen by daily use of a face brush, a facial scrub, etc.