皮膚の構造と美容に関わる病態

抄録

For those who deal with cosmetics, it is recommended to know the normal structure and function of the skin to ensure safe and effective use of cosmetics and cosmetological treatments. The skin is not just a membrane that separates the human body from the outside but has various functions for maintaining homeostasis of the human body. In this paper, we have outlined the normal structure of the skin, touching on the pathological structures related to cosmetology.

The skin consists of three layers: epidermis, dermis, and subcutaneous fat. The epidermis contains four layers: horny layer, granular layer, spinous layer, and basal layer. The horny layer plays a major role of barrier function at the forefront. When the stratum corneum is deficient in intercellular lipids, horny cells become compact and their water retention function is reduced, resulting in “asteatotic eczema,” which is a very common pruritic skin lesion in elderly. With aging, elastic fibers are denatured by long-term exposure to ultraviolet rays, and cause solar elastosis resulting in deep wrinkles. As skin appendages of the dermis, there are hair follicles, sebaceous glands, and sweat glands, which are sites of androgenic alopecia, acne, hyperhidrosis, and osmidrosis, respectively, and exhibit morphological and functional changes. All pathological conditions treated cosmetologically are closely associated with changes in skin structure and function.