Abstracts

A summary of the latest clinical studies

Title: Analysis of U.S. Food and Drug Administration Data on Soft-Tissue Filler Complications Authors: Ortiz AE et al. Published: Dermatologic Surgery, October 2019 Keywords: Complications, Dermal fillers, FDA Abstract: The authors conducted a search of adverse events within the U.S. Food and Drug Administration database that involved injectable dermal fillers for soft-tissue augmentation from June 1993 to August 2014. Search terms included generic and trade names of commercially available soft-tissue fillers. Three thousand seven hundred eighty-two complications involving dermal fillers were identified in the MAUDE database. Forty-four percent of complications implicated hyaluronic acid fillers, 40% involved poly-L-lactic acid fillers, 15% complications included calcium hydroxylapatite fillers, and <1% complications arose from polymethylmethacrylate fillers. Common adverse events included lumps, infection, allergic reaction, ischemia, and swelling. Rare events included trigger of autoimmune reactions, visual disturbances, and stroke.

Title: The Impact of Perceived Stress on Skin Ageing Authors: CM Lee, REB Watson, CE Kleyn Published: European Academy of Dermatology and Venereology, September 2019 Keywords: Stress, Ageing, Psychology Abstract: Skin ageing can be divided according to phenotypical features into intrinsic (by the passage of time) and extrinsic (with the addition of the effects of environmental factors). Photoageing is by far the most researched factor of extrinsic ageing but the additional impact of other factors such as cigarette smoking and exposure to air pollution ought to be taken into account. One of the least researched topics in relation to extrinsic skin ageing is the impact of psychological stress. A contemporary review of response of human skin to stress describes the molecular mechanisms of extrinsic skin ageing, but has fallen short of explaining resilience to stress exhibited by people. Mechanisms to regulate gene expression, define cellular identity and promote functionality are responsible for the adaptive response to stressful events. Conversely, maladaptive response of human tissues to chronic stress appears to have an impact on gene regulation. Epigenetics is the study of heritable changes in organisms due to modifications in gene activity and expression, as opposed to the genetic code (DNA genome). Chronic stress appears to be an important factor in determining an individual’s vulnerability to ageing and age-related comorbidities via epigenetic modifications. Forerunners in epigenetic research recognized the necessity of a reliable biomarker in order to develop a better understanding of the role of epigenomics in ageing. Genomic DNA methylation patterns (DNAm) appear to be valuable in age prediction but variability in specificity exists across species of mammals, human races and tissues. Neuroscience research appears to be leading the way in epigenomics whilst the lack of a valid and reliable DNAm-associated age predictor compatible with human skin tissue hinders research endeavours for the epigenetics of skin ageing. Title: Association of Lifetime Indoor Tanning and Subsequent Risk of Cutaneous Squamous Cell Carcinoma Authors: Lergenmuller S et al. Published: JAMA Dermatology, October 2019 Keywords: Skin cancer, Indoor tanning Abstract: The objective of this study was to investigate the doseresponse association between lifetime indoor tanning and SCC risk, the association between duration of use and age at initiation with SCC risk, and the association between age at initiation and age at diagnosis. This cohort study included data from women born from 1927 to 1963 from the Norwegian Women and Cancer study, established in 1991 with follow-up through December 31, 2015. Baseline questionnaires were issued to participants from 1991 to 2007, with follow-up questionnaires given every 5 to 7 years. A total of 159,419 women (mean [SD] age at inclusion, 49.9 [8.3] years) were included in the study. During follow-up (mean [SD], 16.5 [6.4] years), 597 women were diagnosed with SCC. Risk of SCC increased with increasing cumulative number of indoor tanning sessions. The adjusted hazard ratio (HR) for highest use vs never use was 1.83 (95% CI, 1.38-2.42; P<.001 for trend). A significantly higher risk of SCC was found among women with 10 years or less of use (HR, 1.41; 95% CI, 1.08-1.85) and more than 10 years of use (HR,1.43; 95% CI, 1.161.76) and among women with age at initiation of 30 years or older (HR,1.36; 95% CI, 1.11-1.67) and younger than 30 years (HR,1.51; 95% CI, 1.18-1.92) vs never users. The findings provide supporting evidence that there is a dose-response association between indoor tanning and SCC risk among women. The association between cumulative exposure to indoor tanning and SCC risk was the same regardless of duration of use and age at initiation.

Title: Development ofBotulinum ToxinA-Coated Microneedle for Treating Palmar Hyperhidrosis Authors: Shim DH et al. Published: Molecular Pharmaceutics, October 2019 Keywords: Botulinum toxin, Microneedling, Hyperhidrosis Abstract: Hyperhidrosis is a disorder that produces excess amount of sweat. The botulinum neurotoxin A (BoNT/A) has been used to treat hyperhidrosis through multiple intradermal injections at the site of condition. However, due to its toxicity, it is important to precisely deliver the proper dose of toxin to the target site. In addition, the use of conventional hyperdermic needle for multiple injections in the palm makes the approach undesirable and painful. Here, we designed a BoNT/A-coated microneedle (BoNT-MN) array and tested its efficacy as a substitute pain-free method to treat hyperhidrosis. BoNT-MNs were prepared by coating BoNT/A formulation on polylactic acid microneedles and were found to successfully penetrate in vitro thick skin. The coating formulations were then tested for its stability at 4°C, 25°C, and 37°C for 24 h. BoNT-MNs were found to be much more stable than its liquid state. Additionally, we carried out in vivo experiments by treating the right paw of mice with BoNTMNs and found that the treatment induced a significant reduction of sweating response in the mouse’s foot pads. Thus, BoNT/A treatment with microneedles is beneficial and may be used as a more efficient and less painful approach to treat hyperhidrosis.