Photoaging versus Chronological Aging – A Histological Study on Human Female Skin

Abstract

Background: Photoaging of skin is the premature and irreversible aging occurring due to sunlight exposure, mainly ultraviolet radiation. Due to changes in the structure of DNA, it is considered to be dangerous. Photoaging occurs most commonly in the exposed areas of the skin. Pigmentation, tanning, freckles, and age spots are some of its manifestations, which can even lead to cancer. In sun-protected areas, these features are less observed. A deeper understanding of the normal microscopic features of all age groups is indispensable for advanced detection of the pathology of photo exposure, if any. Hence, a descriptive study on the histology of human female skin based on the effect of sunlight exposure was conducted with the aim of finding out the influence of sunlight on skin aging. Methodology: Thirty-four tissue samples of human skin, each from the ventral wall of the abdomen and extensor aspect of the forearm from female bodies subjected to autopsy were collected and grouped into two different categories based on sunlight exposure. The changes in the thickness of the epidermis were observed in four different age groups using hematoxylin and eosin stains. The statistics obtained were organized with the help of a master chart in Microsoft Excel and examined. Mean and P values were analyzed. Results: Mean epidermal thickness of exposed and unexposed skin showed an increase chronologically (P < 0.001) up to 60 years. The exposed skin showed significantly more epidermal thickness than unexposed skin (P < 0.001). Conclusions: Mean epidermal thickness in females is significantly higher in exposed skin than in unexposed skin in all age groups.