Résumé : The clinical features of photoaged skin are somewhat different from those due to chronological aging. In the epidermis, melanin pigment is a good indicator of the photodamage and pigmentary changes are one of the most visible markers of photoaged skin.
According to the Glogau photoaging classification, in type I corresponding to early photoaging, mid-pigmentary changes are present. Glogau II photoaging is characterized by the visibility of early actinic lentigines. In Glogau III i.e., advanced photoaging, the skin dyschromia is obvious.
Exposed skin of the elderly is usually unevenly pigmented with a mottled appearance, demonstrating that chronic sun-exposure to UV-radiations may severely damage the melanocyte system of the skin, resulting in both hyper and hypomelanotic lesions. The mottled, irregular areas of pigmentation of photoaged skin may be explained by the increased dopa-positivity of melanocytes in the chronically sun-exposed skin and by an irregular distribution of melanosomes within epidermal keratinocytes.