Alterations in Human Dermal Connective Tissue with Age and Chronic Sun Damage

Aged unexposed human skin has decreased hexosamine (22), decreased solubility of dermal collagen (1), and increased hydroxyproline (22), with few dramatic histological alterations (8) as compared with young skin. In contrast, the identity of the histopathologic changes in chronically sun-damaged skin (actinic elastosis) has been debated for many years (5, 6, 9, 10, 23). These changes in exposed skin are caused primarily by prolonged and repeated actinic damage (7,8,11,21,23).