The dermis is primarily composed of the extracellular matrix (ECM) and fibroblasts. During the aging process, the dermis undergoes significant changes. Collagen, which is a major component of ECM, becomes fragmented and coarsely distributed, and its total amount decreases. This is mainly due to increased activity of matrix metalloproteinases, and impaired transforming growth factor-β signaling induced by reactive oxygen species generated during aging. The reduction in the amount of collagen hinders the mechanical interaction between fibroblasts and the ECM, and consequently leads to the deterioration of fibroblast function and further decrease in the amount of dermal collagen. Other ECM components, including elastic fibers, glycosaminglycans (GAGs), and proteoglycans (PGs), also change during aging, ultimately leading to a reduction in the amount of functional components. Elastic fibers decrease in intrinsically aged skin, but accumulate abnormally in photoaged skin. The changes in the levels of GAGs and PGs are highly diverse, and previous studies have reported conflicting results. A reduction in the levels of functional dermal components results in the emergence of clinical aging features, such as wrinkles and reduced elasticity. Various antiaging approaches, including topicals, energy-based procedures, and dermal fillers, can restore the molecular features of dermal aging with clinical efficacy. This review summarizes the current understanding of skin aging at the molecular level, and associated treatments, to put some of the new antiaging technology that has emerged in this rapidly expanding field into molecular context.

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We showed that the face shows definitive regional and seasonal variations in sebum secretion. To define the combination skin type, seasonal variations in sebum secretion should be considered in addition to regional variations.

BackgroundAndrogenetic alopecia (AGA) is a common hair loss disease with genetic predisposition among men and women, and it may commence at any age after puberty. It may significantly affect a variety of psychological and social aspects of one's life and the individual's overall quality of life (QoL).ObjectiveThis study aimed to investigate the QoL of AGA patients and discover the factors that can influence the QoL of AGA patients, including previous experience in non-medical hair care, reasons for hospital visits, age, duration, and the severity of AGA.MethodsA total of 998 male patients with AGA were interviewed, using the Hair Specific Skindex-29 to evaluate the QoL of AGA patients.ResultsThe results of the Hair Specific Skindex-29 on patients with AGA were as follows: symptom scale: 26.3±19.5, function scale: 24.0±20.1, emotion scale: 32.1±21.8, and global score: 27.3±19.1. According to this assessment, QoL was more damaged if the patient had severe alopecia, a longer duration of AGA, younger age, had received previous non-medical hair care, and visited the hospital for AGA treatment.ConclusionThis study showed that AGA could harmfully affect the patients' QoL. These findings indicate that dermatologists should address these QoL issues when treating patients with alopecia.