Recent Demographic Changes and Consequences for Dermatology -- Clinical and Histological Features of Intrinsic versus Extrinsic Skin Aging -- Ethnic Differences in Skin Aging -- Photoaging of Skin -- Premature Skin Aging by Infrared Radiation, Tobacco Smoke and Ozone -- The Role of Hormones in Intrinsic Aging -- Permeability and Antioxidant Barriers in Aged Epidermis -- Clarifying the Vitamin D Controversy: The Health Benefits of Supplementation by Diet Versus Sunshine -- Modern Photoprotection of Human Skin -- Vitamins and Polyphenols in Systemic Photoprotection -- Hormone Replacement Therapy and Skin Aging -- Skin Aging in Three Dimensions -- Retinoid Therapy for Photoaging -- Topical Photodynamic Therapy -- Botulinum Toxin, Fillers, Peels: The Scientific View -- Lasers.