Photoaging versus intrinsic aging: A morphologic assessment of facial skin*

Abstract

Histologic studies have become increasingly important in recognizing morphologic differences in photoaged versus intrinsically aged skin. Earlier histologic studies have attempted to evaluate these changes by examining anatomical sites which are not comparable, such as face and buttocks. As part of a multicenter study, we have quantitatively examined a panel of 16 histologic features in baseline facial skin biopsies from 158 women with moderate to severe photodamage. When compared to the postauricular area (photo protected), biopsies of the crow's feet area (photo exposed) had a twofold increase in melanocytes and a statistically significant increase in melanocytic atypia (p < .0001) and epidermal melanin (p < .0001). Other epidermal changes included reduced epidermal thickness (p < .01), more compact stratum corneum (p < .0001) and increased granular layer thickness (p < .0001) in the crow's feet skin. There was increased solar elastosis (p < .0001), dermal elastic tissue (p < .0001), melanophages (p < .0001), perivascular inflammation (p < .05) and perifollicular fibrosis (p < .01) but no change in the number of mast cells or dermal mucin in the photo exposed skin. Our data document quantitative differences in photoaged versus intrinsically aged facial skin and provides the groundwork for future studies to evaluate the efficacy of new treatments for photoaged skin.

Pseudoxanthoma elasticum–like papillary dermal elastolysis: A large case series with clinicopathological correlation

“…11 On pathology, sun-exposed skin shows statistically increased number of melanophages in the dermis when compared with photoprotected skin. 12 Similar findings are seen in poikiloderma of Civatte. 13 We identified melanophages in the papillary dermis of PXE-like PDE in nearly all cases (88.2%).…”

Optimum pulse duration and radiant exposure for vascular laser therapy of dark port-wine skin: a theoretical study

“…Several studies that have been reported in the literature measured the melanin content for various skin types and suggest that p mel ranges from approximately 3% for light skin to 50% for dark skin. [31][32][33][34][35] We represent light, moderately pigmented, and dark skin by using the values p mel ϭ 5, 25, 50%, respectively.…”

Comparison of Histological Measures of Skin Photoaging

“…In habitually sun-exposed skin keratinocytes vary in size and shape with clusters of p53-positive cells [5], though not all studies show this [6]. Melanosome distribution among keratinocytes is irregular [7], and increases in melanin content and in melanocytic atypia are often found [8]. There is also a flattening of the rete ridges, the finger-like protrusions at the dermal-epidermal junction (DEJ) interface [4].…”