Clinical Characteristics of Photoaging and Pigmentary Changes

The clinical characteristics of photoaged skin are more pronounced compared with those observed in intrinsic aging (Table 3.1). It is these changes that are of cosmetic concern to many individuals as they overshadow those associated with intrinsic aging. In intrinsic aging, the skin has a pale appearance with fine wrinkling. It has been demonstrated that the dermis thins by 20% with intrinsic aging, with the most prominent thinning after the eighth decade [23, 24]. Additionally, melanocytes also decrease during adulthood, with an estimated decrease of 10% per decade [25]. As expected, pigmentary changes are not a prominent feature of intrinsically aged skin compared with photoaged skin (Fig. 3.2). Environmental factors that contribute to aging, such as pollution and smoking, produce marked wrinkling of the skin but not pigmentary abnormalities. There are several different manifestations of pigmentary alterations associated with photoaged skin. These include mottled hyperpigmentation, solar lentigines, diffuse hyperpigmentation, pigmented seborrheic keratoses, and guttate hypopigmentation. Some manifestations of photoaging are more prominently displayed in certain racial groups compared with others. These differences will be discussed below and are highlighted in Table 3.2.

Table 3.1. Clinical characteristics of intrinsic aging and photoaging   Clinical characteristic   Intrinsic aging   Photoaging   Pigmentation   Pale,white, hypopigmentation   Mottled, confluent, and focal hyperpigmentation   Wrinkling   Fine lines   Deep furrows   Hydration   Dry and flakey   Dry and rough   Growths   Benign   Cancerous and benign

Table 3.2. Pigmentary characteristics of photoaging in Asian,African American and Caucasian skin   Clinical Feature Asian African American Caucasian   Ephelides + - ++   Lentigines ++ - ++   Mottled hyperpigmentation + + ++   Seborrheic keratoses ++ + -   Dermatosis papulosa nigra - ++ -