Photodermatology, photoimmunology & photomedicine最新文献

Background: Sunburn can increase one's risk of developing skin cancer. We aimed to quantify the prevalence of sunburn during recreational outdoor sport (ROS) in summer, to explore the use of different sun protection measures, and to examine factors associated with sunburn during ROS using a population-based sample from Germany.

Methods: For this cross-sectional study, 2081 individuals aged 16-65 years who reported being engaged in ROS in summer were surveyed via standardized telephone interviews in 2020 (National Cancer Aid Monitoring, NCAM).

Results: Overall, 16.7% reported experiencing at least one sunburn during ROS in the past twelve months. Sunburn occurrence was negatively associated with the age of the participants (e.g. OR = 0.49 in 56-65 year-olds, p < .001), and positively associated with skin type I/II (OR = 1.55, p < .001) and with having a higher number of nevi (OR = 1.42, p = .005). While wearing sleeved shirts was the most frequently-used sun protection measure during ROS (74.9%), wearing headgear was least common in our sample (29.0%). In multivariate analyses, sunburn was positively associated with the use of sun protection measures (e.g. OR = 1.32 for wearing sleeved shirts, p = .02).

Conclusions: Our nationwide data show that ROS is one of the settings where sun protection should play a greater role. Especially in organized sports, particular attention should be devoted to organizational (e.g. exercise outside peak hours) or contextual measures (e.g. shade by the natural or built environment) to prevent skin cancer in later life.

Background/purpose: Ultraviolet (UV) radiation has both harmful and beneficial effects on human skin and health. It causes skin damage, aging, and cancer; however, it is also a primary source of vitamin D. Additionally, UV radiation can impact energy metabolism and has protective effects on several cardiovascular and metabolic disorders in mice and humans. However, the mechanisms of UV protection against these diseases have not been clearly identified.

Methods: This review summarizes the systemic effects of UV radiation on hypertension and several metabolic diseases such as obesity, diabetes, and nonalcoholic fatty liver disease (NAFLD) in mice, and we also consider the mechanisms of action of the related regulators nitric oxide (NO) and vitamin D.

Results: UV exposure can lower blood pressure and prevent the development of cardiovascular diseases and metabolic disorders, such as metabolic syndrome, obesity, and type 2 diabetes, primarily through mechanisms that depend on UV-induced NO. UV radiation may also effectively delay the onset of type 1 diabetes through mechanisms that rely on UV-induced vitamin D. UV-induced NO and vitamin D play roles in preventing and slowing the progression of NAFLD.

Conclusion: UV exposure is a promising nonpharmacological intervention for cardiovascular and metabolic disorders. NO and vitamin D may play a crucial role in mediating these effects. However, further investigations are required to elucidate the exact mechanisms and determine the optimal dosage and exposure duration of UV radiation.

Background: Ablative carbon dioxide (CO₂ ) laser is still a cornerstone in the management of xanthelasma. However, post-laser complications such as post-inflammatory hyperpigmentation or scarring have to be considered. Heparin sodium was recently suggested as an effective therapeutic modality for xanthelasma.

Objective: The aim of this work was to compare the therapeutic value of ablative CO₂ laser versus intradermal heparin sodium in xanthelasma.

Methods: This study was piloted on 30 xanthelasma patients, whose lesions were randomly categorized into two groups. Group A was managed with CO₂ laser ablation (2 sessions scheduled every 4 weeks), whereas Group B was managed with intradermal heparin sodium injections (10 sessions scheduled every week). Pre- and post-treatments evaluations were done both clinically and dermoscopically.

Results: Significant reduction of xanthelasma lesions was reported in response to both therapeutic interventions. However, the ablative CO₂ laser was more significantly effective than intradermal heparin sodium. Interestingly, intradermal injection of heparin sodium was nearly as effective as ablative CO₂ laser in early (<2 years duration) grade I and II xanthelasma, with a lower incidence of post-therapy side effects.

Conclusions: Intradermal injection of heparin sodium could be suggested as a safe and cost-effective therapeutic technique for early mild grade I and II xanthelasma. Moreover, it could be recommended as a pre-operative management of grade III and IV xanthelasma to reduce the lesions to be easily ablated with CO₂ laser.

Background: Xeroderma pigmentosum (XP) is a rare autosomal-recessive genodermatosis resulting from a DNA-repair defect syndrome. The purpose was to evaluate the prevention on new malignant lesions in patients taking a supplement with Fernblock® (Polypodium leucotomos extract [PLE]) and secondarily correlation with the photoprotective behavior.

Methods: A prospective, single-center and open cohort study was conducted over a 12-month period. The study was performed in Morocco. Optimal photoprotection behavior was recommended. Patients were instructed to take one capsule containing 480 mg of Fernblock® and 5 mcg vitamin D and to apply sunscreen with a SPF50+ and Fernblock® every 2 h during sun exposure. The demographic, clinical, and dermatoscopic patient data were collected at baseline (T0) and following visits at 3 months (T3), 6 months (T6), and 12 months (T12) when it was assessed: Investigator Global Assessment (IGA), Patient/Guardian Global Assessment (PGA), Patient/Guardian Satisfaction Questionnaire, and Photographic and Adverse Events Registration. Pertinent statistical study was performed.

Results: Eighteen patients completed the study. Eleven patients (61%) finished the study without new lesions. Seven patients developed new lesions by the end of the study. Among them, only 30% showed an ideal photoprotective behavior. The lack of an optimal photoprotective behavior increased the probability of developing lesions by 2.5 times with 95% confidence interval.

Conclusions: In our study, more than 60% of patients taking a supplement with Fernblock® did not develop new lesions, and furthermore, we detected that patients following almost ideal photoprotection were 2.5 times less likely to develop NMSC lesions.

Background: The current ISO guidelines for minimal erythema dose (MED) determination require assessment of erythema area of UV-irradiated skin sites. However, this parameter has not been adequately quantified in daily practice. The aims of this study were to investigate the dose response on the unprotected skin sites by quantifying the erythema area and intensity and to show the potential for improving the precision and consistency of MEDu determination by developing predictive models.

Methods: Standard radiation tests were conducted on the back of 31 healthy Chinese volunteers and the MEDu site of each subject was clinically determined by dermatologists. Images of test sites were captured 24 h after radiation, and the erythema area (%EA) and intensity (∆a*) were measured by image analysis. The data were fitted to a logistic 3P function to obtain dose-response curves, and a set of logit (inverse-logistic) models were then derived. An erythema area threshold of %EA = 52% was established to predict MEDu based on the clinical endpoints defined by ISO 24444:2019.

Results: Analysis of the clinically determined MEDu sites revealed wide ranges of %EA (62.3 ± 15% SD) and ∆a* (2.96 ± 0.92 SD). The dose response fitted well to a logistic 3P model (mean R²  = 0.965 and 0.975 for %EA and ∆a*, respectively). Applying the area threshold, values of MEDu were determined by the logit model for the test population, which significantly improved the consistency of MEDu determination (52 ± 0% SD and 2.73 ± 0.61 SD for %EA and ∆a*, respectively).

Conclusion: This study demonstrated that the dose response of UV-induced erythema can be quantified and modeled once the erythema area and intensity are measured. The results of this study show the potential to improve the precision and consistency of MEDu determination in an SPF test. The similar potential in photodermatological, therapeutic, and diagnostic applications was also implied.

Background: Skin photoaging is a condition caused by long-term exposure to ultraviolet irradiation, resulting in a variety of changes in the skin, such as capillary dilation, increased or absent pigmentation, dryness, sagging, and wrinkles. Stem cells possess a remarkable antioxidant capacity and the ability to proliferate, differentiate, and migrate, and their main mode of action is through paracrine secretion, with exosomes being the primary form of secretion. Stem cell-derived exosomes contain a variety of growth factors and cytokines and may have great potential to promote skin repair and delay skin ageing.

Methods: This review focuses on the mechanisms of UV-induced skin photoaging, the research progress of stem cell exosomes against skin photoaging, emerging application approaches and limitations in the application of exosome therapy.

Result: Exosomes derived from various stem cells have the potential to prevent skin photoaging.

Conclusion: The combination with novel materials may be a key step for their practical application, which could be an important direction for future basic research and practical applications.

Background: Chronic actinic dermatitis (CAD) is an immune-mediated photodermatosis characterized by a high eosinophil count and total immunoglobulin E (IgE) in the peripheral blood of patients. At present, however, the reasons for their elevation remain unclear.

Objective: The current study aimed to detect changes in inflammatory cytokines in CAD and explore their role in this disease.

Methods: Enzyme-linked immunosorbent assay and Luminex assay were conducted to measure inflammatory factor levels. Immunohistochemical analysis and quantitative real-time polymerase chain reaction were performed to evaluate the expression levels of interleukin-36γ (IL-36γ), IL-8, chemokine (C-C motif) ligand 17 (CCL17), and CCL18. CCK8 kits were used to assess cell proliferation. Immunofluorescence was used to detect nuclear factor κB (NF-κB) p65 nuclear translocation. Western blot analysis was performed to detect the protein expression level of phosphorylated NF-κB (p-NF-κB) p65. Hematoxylin and eosin and Masson trichrome staining were applied to observe histological changes in a chronic photo-damaged mouse model.

Results: Eosinophils, total IgE, IL-36γ, IL-8, tumor necrosis factor α, CCL17, and CCL18 were elevated in CAD. Of note, IL-36γ promoted the proliferation of eosinophilic cells (EOL-1) and the production of IgE in peripheral blood mononuclear cells. IL-36γ also promoted the production of IL-8 and CCL18 in immortalized human keratinocytes (HaCaT cells), while ultraviolet radiation (UVR)-induced IL-36γ via activation of the NF-κB signaling pathway.

Conclusions: IL-36γ was involved in the pathogenesis of CAD and UVR contributed to the production of IL-36γ, which may provide a novel therapeutic target for CAD.