Introduction: Skin aging, which results from intrinsic and extrinsic factors, is characterized by a rough, uneven and wrinkled appearance of the skin at the macroscopic level. At the microscopic level, aging shows lowered keratinocyte turnover, flattened dermal-epidermal junction and reduced collagen fiber density; however, use of skin biopsies to evaluate characteristic properties of these microscopic changes is too limiting for panelists and rarely used. The development of non-invasive techniques is an opportunity to be considered for such evaluations.
View Article and Find Full Text PDFJ Cosmet Dermatol
June 2024
Photodermatol Photoimmunol Photomed
January 2024
Background: Standardized methods for sun protection factor (SPF) testing are still beset with endpoint and method-driven issues, and can be influenced by multiple factors. The purpose of this analysis is to explore the factors influencing the results of sun protection factor (SPF) testing in human subjects according to the ISO 24444:2019 standard. Intrinsic factors, such as baseline skin color, age and gender, the minimal erythemal dose on an unprotected area (MEDu), as well as environmental factors such as season/weather influences, are considered for analysis.
View Article and Find Full Text PDFPhotodermatol Photoimmunol Photomed
September 2023
Background: Two previously published clinical studies by our group assessed erythema and pigmentation responses in outdoor conditions with three reference sunscreens, comparing their effectiveness under the full spectrum of natural sunlight. These studies followed an almost identical protocol but were conducted in two different locations and in two ethnic groups: broadly, Chinese (Singapore) and White European (Mauritius). We analysed the data from these two study populations to compare differences in skin response according to ethnicity.
View Article and Find Full Text PDFSkin of colour or pigmented skin has unique characteristics: it has a higher eumelanin-to-pheomelanin ratio, more mature melanosomes, an increased amount of melanin distributed in the upper layers of the epidermis, and more efficient DNA repair compared with lighter skin. However, individuals with skin of colour are at a significant risk of skin damage caused by ultraviolet radiation, including the development of photodermatoses and photoageing changes such as uneven skin tone, and are predisposed to pigmentary disorders. In fact, one of the most common conditions leading to dermatology consultations by patients with skin of colour is photoexacerbated pigmentary disorders.
View Article and Find Full Text PDFDermatol Ther (Heidelb)
January 2023
The medical literature on aesthetic dermatology has primarily focused on a light-skinned patient population, yet patients of darker skin types have different needs and priorities. In Chinese individuals, key concerns include altered pigmentation, which is perceived to age the individual, and also relates to the Chinese cultural standard of beauty of fair skin; many seek aesthetic treatment for this. Non-invasive cosmetic procedures such as lasers and injections are also gaining in popularity in the Chinese market, but this population is prone to hyperpigmentation as an adverse effect of such procedures.
View Article and Find Full Text PDFIntroduction: The shortcomings of standardized sunscreen testing have been discussed in recent years, noting differences between how sunscreens perform in indoor clinical (in vivo) laboratory testing compared with real-life conditions. We previously developed an outdoor clinical method for ranking sunscreens by performance level. We used this method to test the performance of a new broad-spectrum sunscreen against International Organization for Standardization (ISO) reference products P3, P5 and P8.
View Article and Find Full Text PDFObjectives: The objective of our study is the review of the literature on the efficacy and safety of a novel water-soluble nail strengthened (WSNS) containing hyaluronic acid and Pistacia lentiscus used for the improvement of nail plate diseases.
Materials And Methods: We conducted literature research on PubMed/MEDLINE to identify all the studies reporting the use of hyaluronic acid and P. lentiscus in the improvements of nail alterations.
Clin Cosmet Investig Dermatol
March 2022
Facial seborrheic dermatitis is common in HIV-positive patients, and the presence of facial lesions can affect quality of life. The management and control of lesions can be frustrating for both physicians and patients. In this pilot clinical study, we clinically evaluated the effectiveness of a topical non-steroidal cream in treating mild to moderate facial seborrheic dermatitis in 20 HIV-positive patients.
View Article and Find Full Text PDFPhotodermatol Photoimmunol Photomed
November 2022
Background/purpose: Melasma is a frequent photoexacerbated hyperpigmentary disorder, which can significantly impact on the quality of life. We sought to review the pathogenesis of melasma, and the role of photoprotection in the prevention and treatment of this disorder.
Methods: We conducted a narrative review of the literature.
Actinic keratosis (AK) is the main risk factor for the development of cutaneous invasive squamous cell carcinoma (SCC). It represents the first sign of severe chronic ultraviolet radiation exposure, which has a clear significant effect. Nevertheless, the skin is exposed to many other exposome factors which should be thoroughly considered.
View Article and Find Full Text PDFIntroduction: Most skin disorders, such as atopic dermatitis, psoriasis, skin cancer or age-related skin issues, are the result of a complex interaction between genetic and environmental factors over time. As an external organ, the skin provides the opportunity to study the link between exposure to the environment and several specific biological responses using an exposome approach. The aim of this review was to identify the state of the art of exposome approaches and elucidate the impact of the new era of exposomics on dermatology.
View Article and Find Full Text PDFSolar exposure, for long hours and often at peak times with limited shade available, predisposes athletes to episodic sunburn and chronic damage, causing increased risk of precancerous lesions and skin cancer. Environmental factors and training intensity affect risk. Clothing provides good protection, but changing established "uniforms" may not be possible for reasons of practicality, safety, or simply custom.
View Article and Find Full Text PDFis an abundant and widely distributed temperate sea anemone that can form dense congregations of individuals. Despite the potential severity of its sting, few detailed cases have been reported. We report a case of a severe toxic reaction following an sting in a 35-year-old oceanographer.
View Article and Find Full Text PDFUrea is a hygroscopic molecule (capable of absorbing water) present in the epidermis as a component of the natural moisturizing factor (NMF) and is essential for the adequate hydration and integrity of the stratum corneum. Urea improves skin barrier function including antimicrobial defense by regulating gene expression in keratinocytes relevant for their differentiation and antimicrobial peptide production. It also plays a fundamental role in regulating keratinocyte proliferation.
View Article and Find Full Text PDFPhotodermatol Photoimmunol Photomed
January 2022
Background: Currently, sunscreens' sun protection factor (SPF) and ultraviolet (UV) A protection are tested separately under indoor conditions, without considering external conditions that may affect performance. Studies are often conducted in Caucasian individuals; other racial groups may respond differently.
Methods: An outdoor, double-blind, intra-individual study was performed in 63 healthy Chinese and Caucasian volunteers in Singapore.
Visible light (VL) can induce pigmentary alterations, especially in dark-skinned individuals, and exacerbate photodermatoses and pigmentary disorders. Currently, there is no standardized method for assessing sunscreen protection against VL. On the basis of a critical review of published in vitro and in vivo methods, a VL photoprotection assessment method based on pigmentation is proposed.
View Article and Find Full Text PDFBackground: Melasma is a common skin disorder characterized by alterations in normal skin pigmentation. The objective was to evaluate the efficacy and safety of a skin whitening serum containing niacinamide, hydroxyphenoxy propionic acid, dipotassium glycyrrhizate, glycolic acid, and 4-n-butylresorcinol applied twice daily combined with a spot-preventing SPF50+ sunscreen for treatment of melasma.
Methods: Twelve healthy Caucasian women with melasma (Fitzpatrick skin types II-IV) were enrolled in this pilot clinical study.
Atopic dermatitis (AD) is a chronic inflammatory skin disease with an estimated prevalence of 10-15% in children and 2-10% in adults. Clinically, there is notable phenotypic variability driven by a complex interaction between genetics, immune function, and the environment. Impairment of the skin barrier plays a significant role in the pathogenesis of AD.
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