Senescence in the skin

Abstract

No difference was found between groups of senescent subjects and younger adults in the control of skin temperature, heat radiation and transcutaneous oxygen pressure. Although capillary numbers decline in elderly skin, transcutaneous oxygen pressure at 43 degrees C in elderly skin is no lower than in young subjects. Topical tretinoin (0.05%) increases heat radiation from the skin, but there is no correlation with an improvement in superficial wrinkles. No conclusion is possible regarding the effects of topical tretinoin on transcutaneous oxygen diffusion due to a wide variability in results; sometimes it is increased and sometimes it is decreased. In different regions of the skin, such as the face and thigh, increased skin radiation and skin contact temperature are not associated with increased transcutaneous oxygen diffusion.

Elderly skin and its rejuvenation: products and procedures for the aging skin

“…Hair and nail growth are retarded. Synthesis of vitamin D decreases as time goes by, and last but not least, the immune response is also impaired 10–13 . All these situations lead to alteration of skin functions, such as protection, excretion, secretion, absorption, thermoregulation, and sensory perception.…”

“…Besides the reduction in the number of keratinocytes, epidermal changes associated with aging involve the flattening of its underside, a reduction in the number of Langerhans cells, and also in the number of melanocytes and synthesized melanosomes, leading to reduced pigmentation. 11,12,[14][15][16][17][18] Dermal changes are represented by a reduction of fibroblasts, collagen and elastic fibers, mast cells and macrophages, and also dilation of the lymphatic channels. The dermal-epidermal junction is flattened and the number of hair follicles decreases with age, although their structure remains unchanged.…”

“…The dermal-epidermal junction is flattened and the number of hair follicles decreases with age, although their structure remains unchanged. 11,12,[14][15][16][17][18] There is a progressive reduction in sebum production. Water-binding capacity of the stratum corneum is decreased.…”

“…Besides the reduction in the number of keratinocytes, epidermal changes associated with aging involve the flattening of its underside, a reduction in the number of Langerhans cells, and also in the number of melanocytes and synthesized melanosomes, leading to reduced pigmentation 11,12,14–18 …”

“…Dermal changes are represented by a reduction of fibroblasts, collagen and elastic fibers, mast cells and macrophages, and also dilation of the lymphatic channels. The dermal–epidermal junction is flattened and the number of hair follicles decreases with age, although their structure remains unchanged 11,12,14–18 …”