Keloid scarring: understanding the genetic basis, advances, and prospects

Bioinformatics analysis reveals the diagnostic and therapeutic value of the centrosome replication-related gene SPICE1 in keloid

Keloids are the abnormal accumulation of collagen in the dermis, which leads to the formation of raised fibrous tissue at the site of injury and the development of a hard scar. The underlying pathological mechanisms associated with keloids have not been fully elucidated. In this study, two GEO datasets (GSE44270 and GSE7890) were employed alongside two machine learning algorithms, Support Vector Machine-Recursive Feature Elimination (SVM-RFE) and Random Forest, to identify diagnostic biomarkers associated with centrosome replication. Following identifying these biomarkers, researchers conducted a functional enrichment analysis to elucidate their biological significance and constructed a gene regulatory network to map their interactions. Furthermore, the study investigated the role of SPICE1 in keloid formation, utilizing a mouse model to explore its potential implications in this pathological process. Researchers identified ten diagnostic markers associated with centrosome replication, among which SPICE1 was significantly upregulated in keloid tissues and fibroblasts. In vivo experiments further demonstrated that the overexpression of SPICE1 promotes keloid formation. Additionally, functional enrichment analysis revealed a connection between these markers and immune cells, suggesting that the immune system may play a crucial role in the development of keloids. This study indicates that SPICE1 is a potential diagnostic marker and therapeutic target for keloids. It offers new insights into the pathological mechanisms of keloids and the development of novel treatments.

The Pathophysiology and Management of Pathologic Scarring-a Contemporary Review

Significance: Pathologic scarring occurs secondary to imbalances in the cellular mechanisms of wound healing and affects millions of people annually. This review article aims to provide a concise overview of the pathophysiology and management of pathologic scarring for clinicians and scientists alike. Recent Advances: Contemporary research in the field has identified aberrations in transforming growth factor-β/small mothers against decapentaplegic (TGF-β/SMAD) signaling pathways as key drivers of pathologic scar formation; indeed, this pathway is targeted by many treatment modalities and translational investigations currently underway. Although intralesional injection of corticosteroids has been the gold standard in the treatment of pathologic scarring, studies show greater treatment efficacy with the use of combination injections such as triamcinolone/5-fluorouracil and triamcinolone/botulinum toxin. Adjunctive therapies including ablative fractional carbon dioxide/erbium-doped yttrium aluminum garnet and non-ablative pulsed-dye lasers, microneedling, and carboxytherapy have shown encouraging results in small cohort studies. Translational investigations involving the use of nanogels, RNA interference, and small molecules targeting TGF-β/SMAD pathways are also currently underway and hold promise for the future. Critical Issues: The heterogeneous nature of hypertrophic scars and keloids poses significant challenges in formulating standardized treatment and assessment protocols, thereby limiting the conclusions that can be drawn. Future Directions: Rigorous clinical trials into the individual and synergistic effects of these therapies would be ideal before any definitive conclusions or evidence-based treatment recommendations can be made. Owing to the heterogeneity of the pathology and patient population, well-conducted cohort studies may be the next best option.

Single-cell RNA sequencing reveals the heterogeneity of myofibroblasts in wound repair

Skin wound repair involves myofibroblasts crucial for tissue integrity. This study utilized single-cell RNA sequencing to explore myofibroblast diversity in various wound healing scenarios. Analysis of 89,148 cells from skin ulcers, keloids, and normal scars identified 13 cell clusters. Myofibroblast subcluster analysis unveiled 11 subsets, with subclusters 1 and 9 predominant in ulcers. Subcluster 1 exhibited heightened matrix metalloproteinase expression and involvement in bacterial response and angiogenesis, crucial in inflammation. Tissue validation confirmed subcluster 1 significance., while animal models supported upregulated CA12, TDO2, and IL-7R in chronic ulcers. These findings illuminate myofibroblast heterogeneity and their impact on wound healing, offering insights into potential therapeutic targets.

Assessment of the efficacy and safety of auricular keloids excision followed by 5-aminolevulinic acid photodynamic therapy

BACKGROUND

Auricular keloids are a significant clinical challenge, which adversely affect the life of the patient at the level of aesthetic and psychological well-being. Despite various treatment modalities, a universally effective therapy has yet to be established. Photodynamic therapy (PDT) offers a promising approach by inhibiting the abnormal proliferation of fibroblasts while minimizing damage to surrounding healthy cells and tissues. This study evaluates the clinical outcomes of auricular keloid patients treated with excision followed by 5-aminolevulinic acid photodynamic therapy (ALA-PDT).

METHODS

This study included 8 patients diagnosed with auricular keloids based on pathological examination and clinical presentation. Following surgical excision of the auricular keloids, topical 5-ALA solution was applied for 4 h. Then each lesion was irradiated with 120 J/cm² using a red LED (635-nm laser) for 20 min. Patients received 3-5 courses of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) during and after the surgery.

RESULTS

Among the 8 patients treated, auricular keloids were completely controlled with the combination therapy. During a follow-up period of 2.7 years (range: 1.8-4.1 years), all patients exhibited excellent outcomes with no recurrence of keloids.

CONCLUSIONS

The combination of surgical excision and 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is an effective and safe treatment for auricular keloids. This combined approach shows promise as an alternative clinical treatment for managing auricular keloids.

Genetic influence on scar vascularity after burn injury in individuals of European ancestry: A prospective cohort study

After burn injury there is considerable variation in scar outcome, partially due to genetic factors. Scar vascularity is one characteristic that varies between individuals, and this study aimed to identify genetic variants contributing to different scar vascularity outcomes. An exome-wide array association study and gene pathway analysis was performed on a prospective cohort of 665 patients of European ancestry treated for burn injury, using their scar vascularity (SV) sub-score, part of the modified Vancouver Scar Scale (mVSS), as an outcome measure. DNA was genotyped using the Infinium HumanCoreExome-24 BeadChip, imputed to the Haplotype Reference Consortium panel. Associations between genetic variants (single nucleotide polymorphisms) and SV were estimated using an additive genetic model adjusting for sex, age, % total body surface area and number of surgical procedures, utilising linear and multinomial logistic regression. No individual genetic variants achieved the cut-off threshold for significance. Gene sets were also analysed using the Functional Mapping and Annotation (FUMA) platform, in which biological processes indirectly related to angiogenesis were significantly represented. This study suggests that SNPs in genes associated with angiogenesis may influence SV, but further studies with larger datasets are essential to validate these findings.

Identifying Features for Keloid Scars Subtyping Using K-Modes Clustering

Keloids are pathological scars that form due to abnormal wound healing, characterized by an overgrowth of collagen. They develop beyond the sites of the original lesion and have a high recurrence rate, are cosmetically deforming, can cause irritation, physical discomfort, and psychological stress, and frequently impact the quality of life. Despite an array of therapeutic approaches, both surgical and non-surgical, no solutions have been able to offer long-term relief. Given the limited understanding of keloid etiology, our study employed a novel data-driven approach using the k-modes clustering algorithm to analyze patterns of ICD-10 medical codes documented in patients' medical history within a patient cohort with hypertrophic disorders of the skin to assess which risk factors could be more predictive of an individual having keloid scars. The results show that scar conditions and fibrosis of the skin (L905), burns and corrosion of the shoulder and upper limb, except wrist and hand (T22), trunk (T21), and ankle and foot (T25), were the most significant features found in clusters where keloid occurrence was most frequent. This study demonstrates the value of clustering analysis in identifying key factors associated with keloid scars, which can inform targeted prevention and management strategies in susceptible individuals, potentially reducing the incidence and burden of this challenging condition.

Revisiting roles of mast cells and neural cells in keloid: exploring their connection to disease activity

Background

Mast cells (MCs) and neural cells (NCs) are important in a keloid microenvironment. They might contribute to fibrosis and pain sensation within the keloid. However, their involvement in pathological excessive scarring has not been adequately explored.

Objectives

To elucidate roles of MCs and NCs in keloid pathogenesis and their correlation with disease activity.

Methods

Keloid samples from chest and back regions were analyzed. Single-cell RNA sequencing (scRNA-seq) was conducted for six active keloids (AK) samples, four inactive keloids (IK) samples, and three mature scar (MS) samples from patients with keloids.

Results

The scRNA-seq analysis demonstrated notable enrichment of MCs, lymphocytes, and macrophages in AKs, which exhibited continuous growth at the excision site when compared to IK and MS samples (P = 0.042). Expression levels of marker genes associated with activated and degranulated MCs, including FCER1G, BTK, and GATA2, were specifically elevated in keloid lesions. Notably, MCs within AK lesions exhibited elevated expression of genes such as NTRK1, S1PR1, and S1PR2 associated with neuropeptide receptors. Neural progenitor cell and non-myelinating Schwann cell (nmSC) genes were highly expressed in keloids, whereas myelinating Schwann cell (mSC) genes were specific to MS samples.

Conclusions

scRNA-seq analyses of AK, IK, and MS samples unveiled substantial microenvironmental heterogeneity. Such heterogeneity might be linked to disease activity. These findings suggest the potential contribution of MCs and NCs to keloid pathogenesis. Histopathological and molecular features observed in AK and IK samples provide valuable insights into the mechanisms underlying pain and pruritus in keloid lesions.

Effects of botulinum toxin type A in the prevention and treatment of facial hypertrophic scars: A meta-analysis

A meta-analysis was conducted to comprehensively evaluate the prophylactic and therapeutic efficacy of botulinum toxin type A (BTX-A) in the treatment of facial hypertrophic scars. Computerised searches were performed in databases, from their inception to November 2023, including Embase, Google Scholar, Cochrane Library, Wanfang, PubMed and China National Knowledge Infrastructure databases, focusing on randomised controlled trials (RCTs) that investigated the use of BTX-A for treating facial hypertrophic scars. Two researchers independently screened the literature, extracted data and conducted quality assessments. Stata 17.0 software was employed for data analysis. Seventeen RCTs were ultimately included, involving 1605 patients who underwent facial cosmetic surgery. The analysis revealed that compared with conventional treatments, BTX-A significantly reduced visual analogue scale (VAS) scores (standardized mean difference [SMD]: -3.50, 95% confidence interval [CI]: -5.16 to -1.84, p < 0.001) and Vancouver scar scale (VSS) scores (SMD: -2.86, 95% CI: -4.03 to -1.68, p < 0.001), and narrowed scar width (SMD: -1.80, 95% CI: -2.48 to -1.13, p < 0.001), while also enhancing the overall effectiveness of the treatment. This study indicates that BTX-A is an effective modality in the prophylaxis and treatment of facial hypertrophic scars, significantly alleviating scar-related pain and preventing scar widening, and is thus worthy of broader clinical application.

Natural History of Keloids: A Sociodemographic Analysis Using Structured and Unstructured Data

INTRODUCTION

Keloids are lesions characterized by the growth of dense fibrous tissue extending beyond original wound boundaries. Research into the natural history of keloids and potential differences by sociodemographic factors in the USA is limited. This real-world, retrospective cohort study aimed to characterize a population of patients with keloids compared with matched dermatology and general cohorts.

METHODS

Patients with ≥ 2 International Classification of Diseases codes for keloid ≥ 30 days apart and a confirmed keloid diagnosis from clinical notes enrolled in the OM1 Real-World Data Cloud between 1 January 2013 and 18 March 2022 were age- and sex-matched 1:1:1 to patients without keloids who visited dermatologists ("dermatology cohort") and those who did not ("general cohort"). Results are presented using descriptive statistics and analysis stratified by cohort, race, ethnicity, household income, and education.

RESULTS

Overall, 24,453 patients with keloids were matched to 23,936 dermatology and 24,088 general patients. A numerically higher proportion of patients with keloids were Asian or Black. Among available data for patients with keloids, 67.7% had 1 keloid lesion, and 68.3% had keloids sized 0.5 to < 3 cm. Black patients tended to have larger keloids. Asian and Black patients more frequently had > 1 keloid than did white patients (30.6% vs. 32.5% vs. 20.5%). Among all patients with keloids who had available data, 56.4% had major keloid severity, with major severity more frequent in Black patients. Progression was not significantly associated with race, ethnicity, income, or education level; 29%, 25%, and 20% of the dermatology, keloid, and general cohorts were in the highest income bracket (≥ US$75,000). The proportion of patients with income below the federal poverty line (< US$22,000) and patterns of education level were similar across cohorts.

CONCLUSION

A large population of patients in the USA with keloids was identified and characterized using structured/unstructured sources. A numerically higher proportion of patients with keloids were non-white; Black patients had larger, more severe keloids at diagnosis.

Needle-free electronically-controlled jet injector treatment with bleomycin and lidocaine is effective and well-tolerated in patients with recalcitrant keloids

OBJECTIVES

The treatment of recalcitrant keloids is challenging. Although intralesional bleomycin using conventional needle injectors (CNI) is effective, it has important drawbacks, such as the need for repetitive and painful injections. Therefore, we aimed to evaluate the effectiveness, tolerability and patient satisfaction of intralesional bleomycin with lidocaine administered with a needle-free electronically-controlled pneumatic jet-injector (EPI) in recalcitrant keloids.

METHODS

This retrospective study included patients with recalcitrant keloids who had received three intralesional EPI-assisted treatments with bleomycin and lidocaine. Effectiveness was assessed using the Patient and Observer Scar Assessment Scale (POSAS) at baseline and four to six weeks after the third treatment. Additionally, treatment related pain scores numeric rating scale, adverse effects, patient satisfaction and Global Aesthetic Improvement Scale (GAIS) were assessed.

RESULTS

Fifteen patients with a total of >148 recalcitrant keloids were included. The median total POSAS physician- and patient-scores were respectively 40 and 41 at baseline, and reduced with respectively 7 and 6-points at follow-up ( p < 0.001; p < 0.001). The median pain scores during EPI-assisted injections were significantly lower compared to CNI-assistant injections, (2.5 vs. 7.0, respectively ( p < 0.001)). Adverse effects were mild. Overall, patients were "satisfied" or "very satisfied" with the treatments (14/15, 93.3%). The GAIS was "very improved" in one patient, "improved" in nine patients and "unaltered" in four patients.

CONCLUSIONS

EPI-assisted treatment with bleomycin and lidocaine is an effective, well tolerated, patient-friendly alternative for CNI in patients with recalcitrant keloid scars. Randomized controlled trials are warranted to confirm our findings and improve the clinical management of recalcitrant keloids.

Sufficient mesh polyhedral intralesional injection for treatment of keloids

BACKGROUND

The recurrence of keloids after intralesional injections is significant, and a review of the literature shows an inconsistent range of success rates. In this study, the modified medical proportion and intralesional injection method were intended to enhance the treatment effect.

METHODS

Twenty patients completed the study. Regional block anesthesia (lidocaine, ropivacaine) was performed. Triamcinolone acetonide (40 mg/mL), 5-fluorouracil (25 mg/mL), and ropivacaine (7.5 mg/mL) were configured in a ratio of 2:1:4 and applied on the lesion by reticular injection (horizontal fan-shaped stratified and vertical shaking pressurized injection). The minimum volume of injection per square centimeter was approximately 3.5 mL. The outcome indicators were the Vancouver Scar Scale (VSS), Visual Analogue Scale (VAS), treatment frequency.

RESULTS

The patients had an 82% ± 7% average reduction in VSS scores and 89% ± 13% and 93% ± 10% reductions in VAS scores of pain and pruritus, respectively, after an average of 2.5 ± 0.7 injections administered within 1 year.

CONCLUSION

The sufficient mesh polyhedral intralesional injection can achieve excellent results for the treatment of keloid scars.

Translational Research Techniques for the Facial Plastic Surgeon: An Overview

The field of facial plastic and reconstructive surgery (FPRS) is an incredibly diverse, multispecialty field that seeks innovative and novel solutions for the management of physical defects on the head and neck. To aid in the advancement of medical and surgical treatments for these defects, there has been a recent emphasis on the importance of translational research. With recent technological advancements, there are now a myriad of research techniques that are widely accessible for physician and scientist use in translational research. Such techniques include integrated multiomics, advanced cell culture and microfluidic tissue models, established animal models, and emerging computer models generated using bioinformatics. This study discusses these various research techniques and how they have and can be used for research in the context of various important diseases within the field of FPRS.

Silicone gel sheeting for treating keloid scars

BACKGROUND

Keloid scarring is one of the most common types of pathological scarring. Keloid scars that fail to heal can affect a person's physical and psychological function by causing pain, pruritus, contractures, and cosmetic disfigurement. Silicone gel sheeting (SGS) is made from medical-grade silicone reinforced with a silicone membrane backing and is one of the most commonly used treatments for keloid scars. However, there is no up-to-date systematic review assessing the effectiveness of SGS for keloid scars. A clear and rigorous review of current evidence is required to guide clinicians, healthcare managers and people with keloid scarring.

OBJECTIVES

To assess the effectiveness of silicone gel sheeting for the treatment of keloid scars compared with standard care or other therapies.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was December 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that recruited people with any keloid scars and assessed the effectiveness of SGS.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment, data extraction and GRADE assessment of the certainty of evidence. We resolved initial disagreements by discussion, or by consulting a third review author when necessary.

MAIN RESULTS

Two studies met the inclusion criteria. Study sample sizes were 16 and 20 participants. The trials were clinically heterogeneous with differences in causes for scarring (e.g. surgery, infected wounds, and trauma), site (e.g. chest and back), and ages of scars. The duration of follow-up was three and four and a half months. The included studies reported three comparisons; SGS compared with no treatment, SGS compared with non-silicone gel sheeting (a dressing similar to SGS but which does not contain silicone), and SGS compared with intralesional injections of triamcinolone acetonide. One trial had a split-body design and one trial had an unclear design (resulting in a mix of paired and clustered data). The included studies reported limited outcome data for the primary review outcome of scar severity measured by health professionals and no data were reported for severity of scar measured by patients or adverse events. For secondary outcomes some data on pain were reported, but health-related quality of life and cost-effectiveness were not reported. Both trials had suboptimal outcome reporting, thus many domains in the risk of bias were assessed as unclear. All evidence was rated as being very low-certainty, mainly due to risk of bias, indirectness, and imprecision.  SGS compared with no treatment Two studies with 33 participants (76 scars) reported the severity of scar assessed by health professionals, and we are uncertain about the effect of SGS on scar severity compared with no treatment (very low-certainty evidence, downgraded once for risk of bias, once for inconsistency, once for indirectness, and once for imprecision). We are uncertain about the effect of SGS on pain compared with no treatment (21 participants with 40 scars; very low-certainty evidence, downgraded once for risk of bias, once for inconsistency, once for indirectness, and once for imprecision). No data were reported for other outcomes including scar severity assessed by patients, adverse events, adherence to treatment, health-related quality of life and cost-effectiveness. SGS compared with non-SGS One study with 16 participants (25 scars) was included in this comparison. We are uncertain about the effect of SGS on scar severity assessed by health professionals compared with non-SGS (very low-certainty evidence, downgraded once for risk of bias, once for indirectness, and once for imprecision). We are also uncertain about the effect of SGS on pain compared with non-SGS (very low-certainty evidence, downgraded once for risk of bias, once for indirectness, and once for imprecision). No data were reported for other outcomes including scar severity assessed by patients, adverse events, adherence to treatment, health-related quality of life and cost-effectiveness. SGS compared with intralesional injections of triamcinolone acetonide One study with 17 participants (51 scars) reported scar severity assessed by health professionals, and we are uncertain about the effect of SGS on scar severity compared with intralesional injections of triamcinolone acetonide (very low-certainty evidence, downgraded once for risk of bias, once for indirectness, and once for imprecision). This study also reported pain assessed by health professionals among 5 participants (15 scars) and we are uncertain about the effect of SGS on pain compared with intralesional injections of triamcinolone acetonide (very low-certainty evidence, downgraded once for risk of bias, once for indirectness, and twice for imprecision). No data were reported for other outcomes including scar severity assessed by patients, adverse events, adherence to treatment, health-related quality of life and cost-effectiveness.

AUTHORS' CONCLUSIONS

There is currently a lack of RCT evidence about the clinical effectiveness of SGS in the treatment of keloid scars. From the two studies identified, there is insufficient evidence to demonstrate whether the use of SGS compared with no treatment, non-SGS, or intralesional injections of triamcinolone acetonide makes any difference in the treatment of keloid scars. Evidence from the included studies is of very low certainty, mainly driven by the risk of bias, indirectness, and imprecision due to small sample size. Further well-designed studies that have good reporting methodologies and address important clinical, quality of life and economic outcomes are required to reduce uncertainty around decision-making in the use of SGS to treat keloid scars.

The effects of mechanical force on fibroblast behavior in cutaneous injury

Wound healing results in the formation of scar tissue which can be associated with functional impairment, psychological stress, and significant socioeconomic cost which exceeds 20 billion dollars annually in the United States alone. Pathologic scarring is often associated with exaggerated action of fibroblasts and subsequent excessive accumulation of extracellular matrix proteins which results in fibrotic thickening of the dermis. In skin wounds, fibroblasts transition to myofibroblasts which contract the wound and contribute to remodeling of the extracellular matrix. Mechanical stress on wounds has long been clinically observed to result in increased pathologic scar formation, and studies over the past decade have begun to uncover the cellular mechanisms that underly this phenomenon. In this article, we will review the investigations which have identified proteins involved in mechano-sensing, such as focal adhesion kinase, as well as other important pathway components that relay the transcriptional effects of mechanical forces, such as RhoA/ROCK, the hippo pathway, YAP/TAZ, and Piezo1. Additionally, we will discuss findings in animal models which show the inhibition of these pathways to promote wound healing, reduce contracture, mitigate scar formation, and restore normal extracellular matrix architecture. Recent advances in single cell RNA sequencing and spatial transcriptomics and the resulting ability to further characterize mechanoresponsive fibroblast subpopulations and the genes that define them will be summarized. Given the importance of mechanical signaling in scar formation, several clinical treatments focused on reducing tension on the wound have been developed and are described here. Finally, we will look toward future research which may reveal novel cellular pathways and deepen our understanding of the pathogenesis of pathologic scarring. The past decade of scientific inquiry has drawn many lines connecting these cellular mechanisms that may lead to a map for the development of transitional treatments for patients on the path to scarless healing.

New Device for Submental Endotracheal Intubation: A Prospective Cohort Study

PURPOSE

Silveira et al (2020) described a new device that aims to facilitate submental intubation. This study aimed to verify the clinical complications from using this new device for submental endotracheal compared to the conventional technique.

MATERIAL AND METHODS

Patients who underwent submental intubation with the orotracheal tube transposition device were compared to those who underwent the conventional technique in a prospective cohort study. The primary predictor variable was intubation technique: conventional versus device-assisted. The primary outcome was total complications (all complications trans and postoperative, were recorded). Secondary variables were 1) age, 2) sex, 3) etiology, 4) race/ethnicity, 5) fracture types, and 6) intubation procedure time. The data were analyzed using descriptive and inferential statistics. Differences were considered statistically significant at P < .05.

RESULTS

Forty-two cases are described, including 24 cases with the device and 18 cases using the conventional technique. The mean age was 30.5 ± 11.228 years. The majority of patients were of male sex (88%), non-white (64%), and victims of motorcycle accidents (33%). The mean time to perform submental intubation was 9.9 minutes (±2.1293). Nine complications were recorded, including 2 intraoperative (2 tube dislocations) and 7 postoperative (5 unesthetic scars, one localized hematoma, and one skin infection). The technique used did not affect the time to submental intubation (P = .610). There was no association between technique and occurrence of intraoperative (P = .679; RR = 0.75; confidence interval [CI], 0.05-11.2), postoperative (P = .656; RR = 1.000; CI, 0.255-3.922), or total complications (P = .602; RR = 0.938; CI, 0.293-3.003).

CONCLUSION

The new device proposed seems to be a good option with similar complication rates as compared to conventional submental intubation.

Scarless wound healing: Current insights from the perspectives of TGF-β, KGF-1, and KGF-2

The process of wound healing involves a complex and vast interplay of growth factors and cytokines that coordinate the recruitment and interaction of various cell types. A series of events involving inflammation, proliferation, and remodeling eventually leads to the restoration of the damaged tissue. Abrogation in the regulation of these events has been shown to result in excessive scarring or non-healing wounds. While the process of wound healing is not fully elucidated, it has been documented that the early events of wound healing play a key role in the outcome of the wound. Furthermore, high levels of inflammation have been shown to lead to scarring. The regulation of these events may result in scarless wound healing, especially in adults. The inhibition of transforming growth factor-β (TGF-β) and the administration of keratinocyte growth factors (KGF), KGF-1 and KGF-2, has in recent years yielded positive results in the acceleration of wound closure and reduced scarring. Here, we encapsulate recent knowledge on the roles of TGF-β, KGF1, and KGF2 in wound healing and scar formation and highlight the areas that need further investigation. We also discuss potential future directions for the use of growth factors in wound management.

Scar Perception: A Comparison of African American and White Self-identified Patients

Scars can have significant morbidity and negatively impact psychological, functional, and cosmetic outcomes as well as the overall quality-of-life, especially among ethnic minorities. The objective of this study was to evaluate African American and White patients' perception of their scars' impact on symptoms, appearance, psychosocial health, career, and sexual well-being, using validated assessment tools.

Method

A total of 675 abdominoplasty and breast surgery patients from four providers completed the SCAR-Q, and Career/Sexual Well-Being scales via phone or email. A higher score on both assessments indicates a more positive patient perception.

Results

Of the 675 respondents, 77.0% were White, and 23.0% were African American. White patients scored significantly higher on the SCAR-Q (232 ± 79 versus 203 ± 116), appearance (66 ± 26 versus 55 ± 29), and Career/Sexual Well-Being (16 ± 2 versus 15 ± 5) scales than African American patients (P < 0.001, P < 0.001, P < 0.001, respectively). There was no significant correlation between duration after surgery and symptoms or appearance scores for African American patients (P = 0.11, P = 0.37). There was no significant correlation between patient age and SCAR-Q score or time after surgery and psychosocial scores.

Conclusions

African American patients are more likely to have lower perceptions of their scarring appearance, symptoms, psychosocial impact, career impact, and sexual well-being impact than White patients. Scar appearance and symptoms are less likely to improve over time for African American patients. This study highlights the need to address patient ethnicity when considering further follow-up, counseling, or other measures to enhance scar perception.

Remarkable efficiency of surgical shave excision of keloids followed by intralesional injection of Bleomycin. A retrospective study of 314 cases

The aim of this study was to determine the efficiency of a keloid treatment consisting of intradermal surgical shave excision followed by intralesional injections of Bleomycin. A retrospective study performed in the Department of Dermatology, CHU UCL Namur Sainte Elisabeth Clinic, Belgium between 2018 and 2019, on 314 patients with keloids—average age: 32 years (range 19–62). Patients were treated first by surgical shave excision and then after reepithelialization, monthly Bleomycin injections were used until the itching and/or pain ceased and the keloid disappeared. The satisfaction index based on Vancouver Scar Scale on the 314 patients was as follows: 87% of the patients were very satisfied with complete flattening (276 patients), 11% were moderated satisfied with significant flattening (32 patients), and 2% show recurrences (6 patients). Pain and itching disappear totally (100% of patients) based on Visual Analogue Scale. The absence of recurrence within 24 months of the last injection, leads us to believe that this can be a first choice and low‐cost treatment, whatever the phototype and the size of the lesion. This treatment can be given in all regions of the world, including in non‐industrialized or developing countries.

Use of Adipose Stem Cells Against Hypertrophic Scarring or Keloid

Hypertrophic scars or keloid form as part of the wound healing reaction process, and its formation mechanism is complex and diverse, involving multi-stage synergistic action of multiple cells and factors. Adipose stem cells (ASCs) have become an emerging approach for the treatment of many diseases, including hypertrophic scarring or keloid, owing to their various advantages and potential. Herein, we analyzed the molecular mechanism of hypertrophic scar or keloid formation and explored the role and prospects of stem cell therapy, in the treatment of this condition.

OMICS Approaches Evaluating Keloid and Hypertrophic Scars

Abnormal scar formation during wound healing can result in keloid and hypertrophic scars, which is a major global health challenge. Such abnormal scars can cause significant physiological pain and psychological distress and become a financial burden. Due to the biological complexity of scar formation, the pathogenesis of such scars and how to prevent them from forming remains elusive. In this review paper, we delve into the world of "omics" approaches to study abnormal scars and provide examples of genomics, transcriptomics, proteomics, epigenomics, and metabolomics. The benefits of "omics" approaches are that they allow for high-throughput studies and the analysis of 100s to 1000s of genes and proteins with the accumulation of large quantities of data. Currently in the field, there is a lack of "omics" review articles describing pathological scars. In this review, we summarize genome-wide linkage analysis, genome-wide association studies, and microarray data to name a few omics technologies. Such data can provide novel insights into different molecular pathways and identify novel factors which may not be captured through small-scale laboratory techniques.

Long non-coding RNA H19 aggravates keloid progression by upregulating SMAD family member 5 expression via miR-196b-5p

Accumulating evidence suggests that long non-coding RNAs (lncRNAs) participate in the formation and development of keloids, a benign tumor. In addition, lncRNA H19 has been shown to act on the biological processes of keloids. This study aimed to identify other important mechanisms of the effect of lncRNA H19 on keloid formation. The H19, miR-196b-5p, and SMAD family member 5 (SMAD5) expression levels were detected using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and Western blotting. Subcellular localization of lncRNA H19 was detected using a nuclear-cytoplasmic separation assay. Cell viability and proliferation were measured using counting kit-8 and colony formation assays. Bax and Bcl-2 levels were examined using Western blot analysis. The interaction between H19 and miR-196b-5p or SMAD5 was verified using a dual-luciferase reporter assay. H19 and SMAD5 expression was upregulated in keloid tissue and fibroblasts, whereas miR-196b-5p expression was downregulated. Knockdown of H19, overexpression of miR-196b-5p, or knockdown of SMAD5 inhibited the viability and proliferation of keloid fibroblasts and promoted apoptosis. Overexpression of H19 or SMAD5 and knockdown of miR-196b-5p promoted viability and proliferation and inhibited apoptosis. miR-196b-5p was identified as a H19 sponge, and SMAD5 was identified as a miR-196b-5p target. The combination of lncRNA H19 and miR-196b-5p regulates SMAD5 expression and promotes keloid formation, thus providing a new direction for keloid treatment.

Efficacy and safety of botulinum toxin type A for postoperative scar prevention and wound healing improvement: A systematic review and meta-analysis

BACKGROUND

Botulinum toxin type A (BTXA) has shown underlying effects for wound healing improvement. New small clinical trials keep emerging every year and updated evidence-based information is warranted. This study aimed to evaluate the efficacy and safety of BTXA for preventing scarring.

METHODS

Four databases were searched to recruit randomized clinical trials (RCTs) which compared the surgical wounds treated with BTXA vs. those treated with placebo or blank control. The outcomes were primarily quantified by measures including the Vancouver Scar Scale (VSS), Visual Analog Scale (VAS), Stony Brook Scar Evaluation Scales (SBSES), modified SBSES (mSBSES), and scar width. Patients' satisfaction and adverse events were also reported.

RESULTS

In total, 16 RCTs involving 671 cases (510 patients) were included. The outcome showed significant superiority of BTXA in VSS (mean difference [MD] = -1.32, 95% confidence interval [CI]: -2.00 to -0.65, p = 0.0001), VAS (MD = 1.29, 95% CI: 1.05-1.52, p < 0.00001), SBSES or mSBSES (MD = -0.18, 95% CI: -0.27 to -0.10, p < 0.0001), scar width (MD = -0.18, 95% CI: -0.27 to -0.10, p < 0.0001), and patients' satisfaction (risk ratio [RR] = 1.25, 95% CI: 1.06-1.49, p = 0.01). No significant difference of adverse events incidence was observed (RR = 1.46 95% CI: 0.64-3.33, p = 0.36).

CONCLUSIONS

Botulinum toxin type A is effective and safe for postoperative scar prevention and wound healing improvement, especially for facial wounds of Asians. Further studies should manage to standardize the treatment algorithm, while mSBSES is recommended for scar assessment.

Effectiveness of combined microfocused ultrasound with visualization and subdermal calcium hydroxyapatite injections for the management of brachial skin laxity

Background

There is no publication to date on the combined use of microfocused ultrasound with visualization (MFU‐V) and calcium hydroxylapatite (CaHA) for brachial skin laxity.

Aim

To assess the effectiveness of combining MFU‐V with diluted/hyperdiluted CaHA in a single session for treating brachial skin laxity.

Subjects/Methods

Female subjects who had skin laxity in the brachial regions and who desired non‐surgical intervention were enrolled into this prospective, single‐arm pilot study. MFU‐V (Ultherapy^®, Merz North America, Inc. Raleigh, N.C.) was applied using the 4.0 MHz‐4.5 mm and 7.0 MHz‐3.0 mm depth transducers, followed by subdermal injections of diluted (1:1)/hyperdiluted (1:2) CaHA (Radiesse^®, Merz North America, Inc). Subjects were followed for six months after treatment. Objective biophysical skin assessments were conducted using a cutometer (Cutometer^® Dual 580 MPA; Courage & Khazaka, Cologne, Germany). Subjective assessments included the arm visual analogue scale (VAS), global aesthetic improvement scale (GAIS), and subject global satisfaction scale.

Results

Twelve subjects participated in the study. The mean R0 reading (measure of skin firmness) progressively improved from 0.515 mm at baseline to 0.433 mm at 24 weeks (p < 0.05 for 12 and 24 weeks). The mean R2 reading (measure of skin elasticity) and mean arm VAS improved significantly from baseline at all visits (p < 0.05 for all). The majority of subjects at each visit showed improved arm appearance and were satisfied with their treatment. Both procedures were well‐tolerated.

Conclusions

Combined use of MFU‐V with diluted/hyperdiluted CaHA demonstrates significant improvements in both objective and subjective measures of brachial skin laxity.

Silicone gel sheeting for treating hypertrophic scars

BACKGROUND

Each year, in high-income countries alone, approximately 100 million people develop scars. Excessive scarring can cause pruritus, pain, contractures, and cosmetic disfigurement, and can dramatically affect people's quality of life, both physically and psychologically. Hypertrophic scars are visible and elevated scars that do not spread into surrounding tissues and that often regress spontaneously. Silicone gel sheeting (SGS) is made from medical-grade silicone reinforced with a silicone membrane backing and is one of the most commonly used treatments for hypertrophic scars.

OBJECTIVES

To assess the effects of silicone gel sheeting for the treatment of hypertrophic scars in any care setting.

SEARCH METHODS

In April 2021 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that enrolled people with any hypertrophic scars and assessed the use of SGS.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment, data extraction and GRADE assessment of the certainty of evidence. We resolved initial disagreements by discussion, or by consulting a third review author when necessary.

MAIN RESULTS

Thirteen studies met the inclusion criteria. Study sample sizes ranged from 10 to 60 participants. The trials were clinically heterogeneous with differences in duration of follow-up, and scar site. We report 10 comparisons, SGS compared with no SGS treatment and SGS compared with the following treatments: pressure garments; silicone gel; topical onion extract; polyurethane; propylene glycol and hydroxyethyl cellulose sheeting; Kenalog injection; flashlamp-pumped pulsed-dye laser; intense pulsed light  and Gecko Nanoplast (a silicone gel bandage). Six trials had a split-site design and three trials had an unclear design (resulting in a mix of paired and clustered data). Included studies reported limited outcome data for the primary review outcomes of severity of scarring measured by health professionals and adverse events (limited data reported by some included studies, but further analyses of these data was not possible) and no data were reported for severity of scarring reported by patients. For secondary outcomes some pain data were reported, but health-related quality of life and cost effectiveness were not reported. Many trials had poorly-reported methodology, meaning the risk of bias was unclear. We rated all evidence as being either of low or very low certainty, often because of imprecision resulting from few participants, low event rates, or both, all in single studies. SGS compared with no SGS Seven studies with 177 participants compared SGS with no SGS for hypertrophic scars. Two studies with 31 participants (32 scars) reported severity of scarring assessed by health professionals, and it is uncertain whether there is a difference in severity of scarring between the two groups (mean difference (MD) -1.83, 95% confidence interval (CI) -3.77 to 0.12; very low-certainty evidence, downgraded once for risk of bias, and twice for serious imprecision). One study with 34 participants suggests SGS may result in a slight reduction in pain level compared with no SGS treatment (MD -1.26, 95% CI -2.26 to -0.26; low-certainty evidence, downgraded once for risk of bias and once for imprecision). SGS compared with pressure garments One study with 54 participants was included in this comparison. The study reported that SGS may reduce pain levels compared with pressure garments (MD -1.90, 95% CI -2.99 to -0.81;  low-certainty evidence, downgraded once for risk of bias and once for imprecision). SGS compared with silicone gel One study with 32 participants was included in this comparison. It is unclear if SGS impacts on severity of scarring assessed by health professionals compared with silicone gel (MD 0.40, 95% CI -0.88 to 1.68; very low-certainty evidence, downgraded once for risk of bias, twice for imprecision). SGS compared with topical onion extract One trial (32 participants) was included in this comparison. SGS may slightly reduce severity of scarring compared with topical onion extract (MD -1.30, 95% CI -2.58 to -0.02; low-certainty evidence, downgraded once for risk of bias, and once for imprecision). SGS compared with polyurethane One study with 60 participants was included in this comparison. It is unclear if SGS impacts on the severity of scarring assessed by health professionals compared with polyurethane (MD 0.50, 95% CI -2.96 to 3.96; very low-certainty evidence, downgraded once for risk of bias, and twice for imprecision). SGS compared with self-adhesive propylene glycol and hydroxyethyl cellulose sheeting One study with 38 participants was included in this comparison. It is uncertain if SGS reduces pain compared with self-adhesive propylene glycol and hydroxyethyl cellulose sheeting (MD -0.12, 95% CI -0.18 to -0.06). This is very low-certainty evidence, downgraded once for risk of bias, once for imprecision and once for indirectness. SGS compared with Gecko Nanoplast One study with 60 participants was included in this comparison. It is unclear if SGS impacts on pain compared with Gecko Nanoplast (MD 0.70, 95% CI  -0.28 to 1.68; very low-certainty evidence, downgraded once for risk of bias and twice for imprecision. There was a lack of reportable data from the other three comparisons of SGS with Kenalog injection, flashlamp-pumped pulsed-dye laser or intense pulsed light.

AUTHORS' CONCLUSIONS

There is currently limited rigorous RCT evidence available about the clinical effectiveness of SGS in the treatment of hypertrophic scars. None of the included studies provided evidence on severity of scarring validated by participants, health-related quality of life, or cost effectiveness. Reporting was poor, to the extent that we are not confident that most trials are free from risk of bias. The limitations in current RCT evidence suggest that further trials are required to reduce uncertainty around decision-making in the use of SGS to treat hypertrophic scars.

Update on management of keloid and hypertrophic scars: A systemic review

Numerous therapeutic strategies have been described for prevention and reduction of hypertrophic scars and keloids, but none of the treatments is effective in all patients. No universal consensus in treatment regimen has been established, and there is limited evidence-based literature to guide the correct management. The process of scar development is complex and requires deeper understanding of the molecular mechanisms that cause their development and recurrences. Despite many available modes of targeting keloid and hypertrophic scars, yet they remain an ongoing challenge to patients and clinicians. To date, no one therapy has been universally accepted as the gold standard for the treatment of all excessive scars nor has the capability of complete scar resolution The search of literature included peer-reviewed articles including clinical trials and scientific reviews. Literature was identified from electronic databases (MEDLINE/PubMed) through May 2021 and references of respective articles and only the articles published in English language were included.

Keloid scars. Modern aspects of diagnosis and treatment

Cicatricial skin hypertrophy includes keloids and hypertrophic scars. Keloid scarring is thought to result from an imbalance between increased synthesis of collagen and extracellular matrix and decreased degradation of these products. Current knowledge of keloid pathophysiology prompts clinicians to investigate new methods for the diagnosis and treatment of keloids, as well as their prevention.

Current Advances in Hypertrophic Scar and Keloid Management

Hypertrophic scars and keloids are caused by excessive tissue response to dermal injury due to local fibroblast proliferation and collagen overproduction. This response occurs because of pathologic wound healing due to dysregulation in the inflammatory, proliferative, and/or remodeling phase. Patients with hypertrophic scars or keloids report reduced quality of life, physical status, and psychological health. Hypertrophic scars or keloids will develop in 30 to 90% of individuals, and despite their prevalence, treatment remains a challenge. Of the treatments currently available for hypertrophic scars and keloids few have been adequately supported by studies with appropriate experimental design. Here, we aim to review the available literature to provide up-to-date information on the etiology, epidemiology, histology, pathophysiology, prevention, and management options available for the treatment of hypertrophic scars and keloids and highlight areas where further research is required.

Risk of cancer development in patients with keloids

Keloid is a skin disease characterized by exaggerated scar formation, excessive fibroblast proliferation, and excessive collagen deposition. Cancers commonly arise from a fibrotic microenvironment; e.g., hepatoma arises from liver cirrhosis, and oral cancers arise from submucosal fibrosis. As keloids are a prototypic fibroproliferative disease, this study investigated whether patients with keloids have an increased cancer risk. In a matched, population-based study, first 17,401 patients treated for keloids during 1998–2010 with 69,604 controls without keloids at a ratio of 1:4 were evaluated. The association between keloids and risk of cancer was estimated by logistic regression or Cox proportional hazard regression models after adjustment of covariates. In total, 893 first-time cases of cancer were identified in the 17,401 patients with keloids. The overall cancer risk was 1.49-fold higher in the keloids group compared to controls. Regarding specific cancers, the keloids group, had a significantly higher risk of skin cancer compared to controls (Relative risk = 1.73). The relative risk for skin cancer was even higher for males with keloids (Relative risk = 2.16). Further stratified analyses also revealed a significantly higher risk of developing pancreatic cancer in female patients with keloids compared to controls (Relative risk = 2.19) after adjustment for known pancreatic cancer risk factors. This study indicates that patients with keloids have a higher than normal risk for several cancer types, especially skin cancers (both genders) and pancreatic cancer (females). Therefore, patients with keloids should undergo regular skin examinations, and females with keloids should regularly undergo abdominal ultrasonography.

Assessment of various intralesional injections in keloid: Comparative analysis

AIM

Intralesional triamcinolone is a gold standard in treating the keloids to comparation its effectiveness versus intralesional 5-fluorouracil intralesional verapamil and intralesional platelet-rich plasma.

PATIENTS AND METHODS

Several 160-cases were categorized into four groups of each Group-Containing 40 cases. Group-A (control) treated with intralesional triamcinolone and Group-B intralesional verapamil, Group-C intralesional 5-fluorouracil, and Group-D intralesional platelet-rich plasma. Patients were assessed for clinical response based on a decrease in the patient and observer scar assessment scale (POSAS) at baseline and the end of treatment.

RESULTS

The mean base-line POSAS score was 91 ± 10.98 SD check-in Group-A, 90 ± 10.85 in Group-B, 89 ± 10.06 in Group-C, and 92 ± 10.84 in Group-D.POSAS score after 24 weeks 36 ± 12.74 in Group-A, 29 ± 10.91 in Group-B, 39 ± 13.74 in Group-C, 36 ± 12.74 in Group-D. Statistically, a significant difference was observed between groups.

CONCLUSION

Intralesional verapamil reported to be the most effective therapy and platelet-rich plasma was effective as intralesional triamcinolone acetonide with no serious side effects and 5-fluorouracil was less effective in treating the keloids.

Association of Leptin Receptor Gene Polymorphisms with Keloids in the Chinese Han Population

BACKGROUND The association between leptin receptor (LEPR) polymorphisms and keloids is still unclear. Our study aimed to explore the association between LEPR gene polymorphisms and keloids in the Chinese Han population. MATERIAL AND METHODS We implemented a case-control study in a cohort of 352 keloid patients and 299 healthy controls to analyze the correlation between 4 SNPs (rs1137101, rs1938496, rs6588147, and rs7555955) and keloids. Genomic DNA was extracted from peripheral blood by using TGuide M16 (Tiangen). Genotyping of LEPR SNPs was performed using an improved multiple ligase detection reaction (iMLDR) by Shanghai Genesky Bio-Tech Co., Ltd. RESULTS We found that patients caring the AA genotype of rs1137101 and the CC genotype rs1938496 tend to have the increased risk of keloids (P=0.026, P=0.047). Carrying the GA, AA gene type, and G allele frequencies of rs7555955, patients were more likely to have to keloids (P=0.030, P=0.016, P=0.018, respectively). There were no significant differences in genotype distribution and allele frequencies of rs6588147 between cases and controls. The association of rs1137101 and rs7555955 under dominant, recessive, and allele models exhibited significant differences among family-history keloid patients, no-family-history keloid groups, and normal controls (χ²=6.471, P=0.039; χ²=6.477, P=0.039; χ²=6.197, P=0.045, respectively). Similarly, the OR of rs1137101 in the recessive model was significantly higher in patients with a family history of keloids than those in controls. Nonetheless, there are significant ORs of rs1938496 and rs6588147 among the mild-moderate keloid, severe keloid, and control groups. CONCLUSIONS The LEPR gene polymorphisms are associated with keloid formation and severity, especially in patients with a positive family history.

The association between keloid and osteoporosis: real-world evidence

Background

Keloids are characterized by disturbance of fibroblast proliferation and apoptosis, deposition of collagen, and upregulation of dermal inflammation cells. This benign dermal fibro-proliferative scarring condition is a recognized skin inflammation disorder. Chronic inflammation is a well-known contributor to bone loss and its sequelae, osteoporosis. They both shared a similar pathogenesis through chronic inflammation. We assessed whether keloids increase osteoporosis risk through using National Health Insurance Research Database.

Methods

The 42,985 enrolled patients included 8597 patients with keloids but no history of osteoporosis; 34,388 controls without keloids were identified from the general population and matched at a one-to-four ratio by age, gender. Kaplan-Meier method was applied to determine cumulative incidence of osteoporosis. Cox proportional hazard regression analysis was performed after adjustment of covariates to estimate the effect of keloids on osteoporosis risk.

Results

Of the 8597 patients with keloids, 178 (2.07%) patients were diagnosed with osteoporosis while in the 34,388 controls, 587 (1.71%) were diagnosed with osteoporosis. That is, the keloids patients had 2.64-fold higher risk of osteoporosis compared to controls after adjustment for age, gender, Charlson Comorbidity Index and related comorbidities. The association between keloids and osteoporosis was strongest in patients younger than 50 years (hazard ratio = 7.06%) and in patients without comorbidities (hazard ratio = 4.98%). In the keloids patients, a high incidence of osteoporosis was also associated with advanced age, high Charlson Comorbidity Index score, hyperlipidemia, chronic liver disease, stroke, and depression.

Conclusions

Osteoporosis risk was higher in patients with keloids compared to controls, especially in young subjects and subjects without comorbidities.

LncRNA H19 promotes keloid formation through targeting the miR-769-5p/EIF3A pathway

Keloid is a skin disease characterized by fibrous hyperplasia, which is often difficult to cure. Long non-coding RNAs (lncRNAs) have been shown to be associated with the development of many diseases. However, the role and mechanism of lncRNA H19 in keloid has been less studied. Our study found that lncRNA H19 expression was increased in keloid tissues and fibroblasts. Besides, H19 knockdown hindered the proliferation, migration, invasion, extracellular matrix (ECM) deposition, and enhanced the apoptosis of keloid fibroblasts. Further experiments showed that microRNA (miR)-769-5p could be sponged by H19, and its knockdown reversed the suppression effect of H19 knockdown on keloid formation. Eukaryotic initiation factor 3A (EIF3A) was found to be a target of miR-769-5p, and its overexpression inverted the inhibition effect of miR-769-5p overexpression on keloid formation. Moreover, the expression of EIF3A was regulated by H19 and miR-769-5p in keloid fibroblasts. Collectively, LncRNA H19 might play an active role in keloid formation, which might provide a new target for the treatment of keloid.

Outcomes of Surgical Excision and High-Dose-Rate Brachytherapy for Earlobe Keloids

BACKGROUND

Radiotherapy as an adjuvant therapy to surgical resection has shown variable rates of recurrence treating earlobe keloids. The purpose of this study was to describe our experience with surgical excision followed by high-dose-rate brachytherapy and present our outcomes after 24 months of follow-up.

METHODS

Retrospective chart of 14 patients with 14 earlobe keloids treated with surgical excision followed by high-dose-rate brachytherapy, between January 2015 and May 2016 were enrolled. Database included demographics, Fitzpatrick skin type, laterality, lesion size, and follow-up visits information. Outcomes were assessed in terms of keloid recurrence rates, complications, and patient subjective aesthetical result satisfaction after 24 months of follow-up.

RESULTS

All procedures were completed without complications. Three patients experienced keloid recurrence after 6 (14.28%) and 12 months (7.14%). Three patients experienced mild signs of self-limited post-radiation dermatitis. Self-assessment of aesthetical result was considered "very good" in 71.43% of patients.

CONCLUSION

Surgical excision followed by high-dose-rate brachytherapy is secure and effective to treat earlobe keloids, and can be considered a first line combined treatment. Larger clinical trials comparing different irradiation protocols are still needed.

An open source pipeline for design of experiments for hyperelastic models of the skin with applications to keloids

The aim of this work is to characterize the mechanical parameters governing the in-plane behavior of human skin and, in particular, of a keloid-scar. We consider 2D hyperelastic bi-material model of a keloid and the surrounding healthy skin. The problem of finding the optimal model parameters that minimize the misfit between the model observations and the in vivo experimental measurements is solved using our in-house developed inverse solver that is based on the FEniCS finite element computational platform. The paper focuses on the model parameter sensitivity quantification with respect to the experimental measurements, such as the displacement field and reaction force measurements. The developed tools quantify the significance of different measurements on different model parameters and, in turn, give insight into a given model's ability to capture experimental measurements. Finally, an a priori estimate for the model parameter sensitivity is proposed that is independent of the actual measurements and that is defined in the whole computational domain. This estimate is primarily useful for the design of experiments, specifically, in localizing the optimal displacement field measurement sites for the maximum impact on model parameter inference.

Neuronal Precursor Cell Expressed Developmentally Down Regulated 4 (NEDD4) Gene Polymorphism Contributes to Keloid Development in Egyptian Population

BACKGROUND

Keloids represent chronic fibroproliferative skin disorders in which there is deposition of extracellular components, especially type 1 collagen, fibronectin and elastin, in excessive amounts. NEDD4 is associated with fibrosis found in abnormal wound healing through increased fibroblast proliferation and regulation of type 1 collagen expression. The exact etiology of keloid formation is undefined, but the role of genetic factors was demonstrated.

OBJECTIVE

To investigate the polymorphism of the NEDD4 gene rs8032158 in a sample of Egyptian patients who have keloids.

METHODS

The current case-control study was conducted in 160 unrelated subjects; 100 keloid patients and 60 ages and sex coincided with apparently healthy controls. All subjects underwent a complete history, and weight and length were measured to calculate body mass index (BMI). The Vancouver Scar Scale (VSS) was used to assess keloid severity. An analysis of the polymorphism of the NEDD4 gene rs8032158 T/C was performed using taqman allelic discrimination (real-time PCR).

RESULTS

The rs8032158 CC genotype was observed significantly in keloid patients and increased the risk of keloid development by approximately 2 times (p = 0.003, OR = 1.80). The C allele significantly increased the risk of keloid development by approximately 2 times (P = 0.002, OR = 2.08). The carriers of the CC genotype were significantly associated with severe keloid form and with the highest VSS values.

CONCLUSION

The polymorphism of the NEDD4 gene rs8032158 could participate in the formation of keloids in the Egyptian population. The NEDD4 rs8032158 CC genotype may have a role in keloid severity.

Efficacy and Safety of Botulinum Toxin Type A in Preventing Postoperative Scars and Improving the Cosmetic Appearance of Scars: A Systematic Review and Meta-Analysis

BACKGROUND

Scars with poor cosmesis that develop after wound healing may affect normal life.

OBJECTIVE

To assess the efficacy and safety of botulinum toxin type A (BTXA) in preventing postoperative hypertrophic scars or keloids.

METHODS

A systematic review was performed by searching the PubMed, Cochrane Library, and EMBASE databases from their inception date up to February 2020 for randomized controlled trials (RCTs) evaluating the efficacy of BTXA in preventing hypertrophic scars or keloids. The primary outcome measures included the Vancouver Scar Scale (VSS) score, Visual Analog Scale (VAS) score, scar width, patient satisfaction, and adverse events.

RESULTS

Twelve RCTs involving 497 cases (372 patients) were included. The meta-analysis showed significant differences in the VAS score (weighted mean difference [WMD] = 1.31, 95% CI = 1.06 to 1.55, P < .00001), VSS score (WMD = -1.02, 95% CI = -1.72 to -0.32, P = .004), scar width (WMD = -0.18, 95% CI = -0.29 to -0.08, P = .0008), and patient satisfaction (relative risk = 1.25, 95% CI = 1.06-1.49, P = .01). Four studies reported trivial adverse events.

CONCLUSIONS

This meta-analysis showed that BTXA was more effective than the control treatment in preventing postoperative scars and improving the cosmetic appearance of facial scars for East Asians, and no serious adverse events were found during the follow-up period. However, there was insufficient evidence to support the use of BTXA for the prevention of scars in patients from other ethnic groups and regions or scars in non-facial areas.

Identification of Differentially Methylated CpG Sites in Fibroblasts from Keloid Scars

As a part of an abnormal healing process of dermal injuries and irritation, keloid scars arise on the skin as benign fibroproliferative tumors. Although the etiology of keloid scarring remains unsettled, considerable recent evidence suggested that keloidogenesis may be driven by epigenetic changes, particularly, DNA methylation. Therefore, genome-wide scanning of methylated cytosine-phosphoguanine (CpG) sites in extracted DNA from 12 keloid scar fibroblasts (KF) and 12 control skin fibroblasts (CF) (six normal skin fibroblasts and six normotrophic fibroblasts) was conducted using the Illumina Human Methylation 450K BeadChip in two replicates for each sample. Comparing KF and CF used a Linear Models for Microarray Data (Limma) model revealed 100,000 differentially methylated (DM) CpG sites, 20,695 of which were found to be hypomethylated and 79,305 were hypermethylated. The top DM CpG sites were associated with TNKS2, FAM45B, LOC723972, GAS7, RHBDD2 and CAMKK1. Subsequently, the most functionally enriched genes with the top 100 DM CpG sites were significantly (p ≤ 0.05) associated with SH2 domain binding, regulation of transcription, DNA-templated, nucleus, positive regulation of protein targeting to mitochondrion, nucleoplasm, Swr1 complex, histone exchange, and cellular response to organic substance. In addition, NLK, CAMKK1, LPAR2, CASP1, and NHS showed to be the most common regulators in the signaling network analysis. Taken together, these findings shed light on the methylation status of keloids that could be implicated in the underlying mechanism of keloid scars formation and remission.

Understanding Covid and the associated post-infectious hyper-inflammatory state (PIMS-TS) in children

When SARS-CoV2 infection was first reported from China, very few children had severe lung or systemic disease. Approximately six weeks after the first adult cases were reported in the United Kingdom, a small subgroup of children of largely non-white backgrounds, presented with severe hyper-inflammatory disease, most likely associated with Covid. The possible reasons for this ethnic predilection are explored.

Hypoxia and HIF-1α Regulate Collagen Production in Keloids

Keloids are reactive or spontaneous fibroproliferative dermal tumors characterized by the exaggerated and uncontrolled accumulation of extracellular collagen. Current approaches to mitigate keloidogenesis are largely procedural in nature. However, a better understanding of its biological drivers may lead to novel targeted treatments for keloids. Through whole-genome expression analysis, we found that an HIF-1α transcriptional footprint is preferentially upregulated (activation score = 2.024; P = 1.05E-19) in keloid fibroblasts compared with normal dermal fibroblasts. We verified that HIF-1α protein is more strongly expressed in keloid specimens compared with normal skin (P = 0.035) and that hypoxia (1% O₂) leads to increased collagen, especially in the extracellular compartment. Collagen levels were reduced uniformly by selective HIF-1α inhibitor CAY10585. Our results indicate that collagen secretion may be intimately linked to a hypoxic microenvironment within keloid tumors and that HIF-1α blockade could be a novel avenue of treatment for these tumors.

Laser fluorescence spectroscopy in predicting the formation of a keloid scar: preliminary results and the role of lipopigments

Keloid scars, in contrast to other scar types, significantly reduce the patient's quality of life. To develop a nondestructive optical diagnostic technique predicting the keloid scars formation in vivo, laser-induced fluorescence spectroscopy (LFS) was used to study the autofluorescence in skin of patients with various types of head and neck cicatricial deformities. The unexpected results were obtained for the endogenous fluorescence of lipofuscin. Significantly reduced autofluorescence of lipofuscin was registered both in the intact and in the keloid scar tissues in comparison with the intact and scar tissues in patients with hypertrophic and normotrophic scars. Sensitivity and specificity achieved by LFS in keloid diagnosis are 81.8% and 93.9% respectively. It could take place due to the changes in the reductive-oxidative balance in cells, as well as due to the proteolysis processes violation. Therefore, we suppose that the evaluation of the lipofuscin autofluorescence in skin before any surgical intervention could predict the probability of the subsequent keloid scars formation.

Replication study of four keloid-associated polymorphisms in patients of European descent - a single centre study

Keloid is defined as a benign dermal fibro-proliferative growth that extends outside the original wound and invades adjacent dermal tissue. Its pathogenesis is complex and much evidence suggests the influence of genetic factors, including the rs873549, rs1511412, rs940187 and rs8032158 polymorphisms associated with keloid risk in Japanese patients. The aim of our study was to investigate possible associations between rs873549, rs1511412, rs940187 and rs8032158 variants and the risk of keloid in Polish patients of European descent. The genetic polymorphisms were identified by sequencing genomic DNA extracted from peripheral blood leukocytes from 86 keloid patients and from newborn cord blood leukocytes from 100 newborns as a control group. No significant differences (p > 0.05) in the distributions of rs873549, rs1511412, rs940187 and rs8032158 alleles were found between keloid patients and newborn controls (26.7% vs. 25.5%, 9.9% vs.7.0%, 19.8% vs. 12.5%, and 41.9% vs. 33.5%, respectively). Logistic regression with adjustment for gender revealed that only the CC homozygous genotype of rs8032158 polymorphism was significantly more frequent in keloid patients as compared with controls (19.8% vs. 11.0%, respectively). Our results suggest that in contrast to Asian populations only the rs8032158 polymorphism at locus 15q21.3 is associated with the susceptibility to keloid scarring in patients of European descent.

Animal models of scarring control

Filtration surgery has, for the past 50 years been key in the treatment of glaucoma yet a significant issue in the long-term success of such surgery is fibrosis limiting aqueous drainage. Numerous methods have been used to reduce such scarring after filtration surgery and animal models have been important in the development of such techniques. First animal models have been central in understanding molecular and cellular changes occurring in fibrosis and thus which pathways might be valuable therapeutic. Secondly animal models have been critical in determining which of these therapies is likely to be most worthwhile. Having said that animals differ substantially from humans in the anatomy of their aqueous drainage pathways and in the mechanisms of fibrotic change. Rodents and lagomorphs vary more markedly from humans than do primates at an anatomic, biochemical and physiological level, and thus the latter might seem more appropriate as models for antifibrotic techniques. However the welfare implications, and thus ethical issues, in using primates are more concerning than with rodents or rabbits and efforts to refine, reduce and replace living animals in such model systems are crucially important. One problem is that the animal models normally involve healthy eyes, not ones with glaucoma. In veterinary ophthalmology we see large numbers of dogs with glaucoma, many of which have filtration implants placed. Potentially these could be a valuable animal model where benefits of antifibrotic treatment could benefit the animals involved and the research seeking to optimise such treatments.

The role of pharmacogenetics in keloid scar treatment: A literature review

BACKGROUND

The pathophysiology of keloid scars is still not fully understood and a universally reliable effective treatment has not been identified. Pharmacogenetics explores how drug response to a particular therapy can relate to genetic variations.

PURPOSE

To investigate how pharmacogenetics could be applied to keloid scars and the relevance of this to clinical practice.

METHODS

We reviewed the literature and discuss our current knowledge of pharmacogenomics in the treatment of keloid scars. A literature search was performed using the terms 'Pharmacogenetics', 'Pharmacogenomics', 'Keloid' and 'Scar'. We searched the PubMed, MEDLINE and EMBASE databases to find the relevant articles. Only articles in English were chosen. The level of evidence was evaluated and selected accordingly listing the studies with the highest level of evidence first.

RESULTS

Treatments including corticosteroid injections and 5-fluorouracil can be effective in some patients, but less so in others. Polymorphisms of the glucocorticoid receptor and variants of CCL2, YAP1, miR-21-5p and NF-κβ might be responsible for different responses to treatments used in keloid scars such as 5-fluorouracil. Small molecule inhibitors might be utilised to target other implicated genes.

CONCLUSION

Pharmacogenetics aims to produce the most efficacious patient outcomes while reducing adverse effects. Understanding the pharmacogenetics of keloid scars could lead to a new era of personalised medicine in the treatment of keloid scars. At present, there is some evidence (level 3b/4) to suggest genetic variations that are responsible to drug response in keloids, but further research in this field is required.

LAY SUMMARY

The varied response to similar therapeutic treatments in keloids has prompted the consideration of the role of genetic variants on response in the form of pharmacogenetics. Pharmacogenetics refers to drugs and their metabolism and action based on genetic influences. The ideal scenario would involve the selection of treatment based on the individual's specific genetic variants to ensure maximum efficacy with minimal toxicity. Some evidence currently points to genetic variations in some keloid patients that might be of relevance to the treating clinician.

Long non-coding RNA HOXA11-AS accelerates the progression of keloid formation via miR-124-3p/TGFβR1 axis

Emerging evidence reveals the importance of long non-coding RNAs (lncRNAs) in the development and progression of keloid formation, whereas the underlying mechanisms are not well understood. In the present study, we investigated the biological effects and molecular mechanisms of lncRNA HOXA11-AS in keloid formation. First, the expression levels of HOXA11-AS, miR-124-3p, and transforming growth factor β receptor type I (TGFβR1) were measured in both keloid tissues and human keloid fibroblasts (HKFs) using qRT-PCR and western blot analysis, respectively. Next, we adopted both gain- and loss-of-function strategies to explore the significance of HOXA11-AS. TUNEL, flow cytometry, DNA ladder, and tube formation assays were performed to measure cell apoptosis and angiogenesis, respectively. Besides, the potential binding relationship between HOXA11-AS and miR-124-3p, as well as miR-124-3p and TGFβR1 was identified using bioinformatic screening and verified by luciferase reporter assay. Furthermore, we explored the importance of miR-124-3p in HOXA11-AS-induced phenotypes and regulations on TGFβ signaling or PI3K/Akt signaling. We found that HOXA11-AS and TGFβR1 were significantly up-regulated, while miR-124-3p was down-regulated both in keloid tissues or fibroblasts than in normal skin tissues or fibroblasts. Functionally, high expression of HOXA11-AS essentially inhibited cell apoptosis and promoted fibroblast-induced angiogenesis. Mechanistically, miR-124-3p was identified as a downstream effector to be involved in HOXA11-AS-mediated phenotypes through directly targeting TGFβR1, thus modulating PI3K/Akt signaling pathway. Taken together, our findings revealed that HOXA11-AS inhibits cell apoptosis and promotes angiogenesis through miR-124-3p/TGFβR1 axis, contributing to the progression of keloid formation, which might provide a novel target for keloid therapy.

Keloids: Current and emerging therapies

Keloids are pathological scars that grow over time and extend beyond the initial site of injury after impaired wound healing. These scars frequently recur and rarely regress. They are aesthetically disfiguring, can cause pain, itching, discomfort as well as psychological stress, often affecting quality of life. Many treatment modalities, including surgical and non-surgical, have been explored and have been reported to be beneficial; however, none have been absolutely satisfactory or optimal for the treatment of all keloid subtypes to date. This poses a major challenge to clinicians. Often, a combinational therapeutic approach appears to offer the best results with higher patient satisfaction compared to monotherapy. The aetiopathogenesis of keloids is not fully elucidated; however, with recent advances in molecular biology and genetics, insight is being gained on the complex process of scar formation and hence new therapeutic and management options for keloids. In this paper, we explore the literature and summarise the general concepts surrounding keloid development and review both current (corticosteroids, surgical excision, silicone-based products, pressure therapy, radiotherapy, cryotherapy, laser therapy, imiquimod and 5-fluorouracil) and emerging (stem cell therapy, mitomycin C, verapamil, interferons, bleomycin, botulinum toxin type A and angiotensin-converting enzyme inhibitors) treatments. Increased knowledge and understanding in this area may potentially lead to the discovery and development of novel therapeutic options that are more efficacious for all keloid types.

LAY SUMMARY

Keloids are problematic scars that are difficult to treat and manage. The aetiopathogenesis of keloids is not clear; however, recent advances in molecular biology and genetics are beginning to shed light on the underlying mechanisms implicated in keloid scar formation which will hopefully lead to the development of treatment options for all keloid types. This review summarises current and emerging therapies.

Two Functional TP53 Genetic Variants and Predisposition to Keloid Scarring in Caucasians

Introduction

Keloid is defined as a benign proliferative scar that grows beyond the confines of the original insult to the skin, invading into adjacent normal tissue. The pathogenesis of keloid is complex, and many evidences suggest the influence of genetic factors, among them the polymorphisms of the TP53 gene encoding tumor protein p53.

Objective

To investigate the association of rs1042522 (c.215G>C, p.Arg72Pro) and rs17878362 (16-bp insertion/duplication in intron 3) variants, two most frequently analyzed TP53 functional polymorphisms and the risk of keloid in Polish patients.

Materials and Methods

The rs1042522 and rs17878362 polymorphisms were identified by sequencing genomic DNA extracted from peripheral blood leukocytes of 86 keloid patients and from cordial blood leukocytes of 100 newborn infants consisting control group.

Results

The rs1042522 and rs17878362 TP53 genotype distributions both in keloid patients and in the control group conformed to the expected Hardy–Weinberg equilibrium. No significant differences in the distribution of rs1042522 and rs17878362 TP53 alleles or genotypes have been found between keloid patients and newborn controls. There is tight, but not complete, linkage disequilibrium between rs1042522 and rs17878362 TP53 polymorphisms (D′ = 0.667, r = 0.448, and p=0). No significant differences in the distribution of rs1042522 and rs17878362 TP53 haplotypes or diplotypes have been found between keloid patients and newborn controls.

Conclusions

Our results suggest the lack of association of rs1042522 and rs17878362 TP53 polymorphisms and their haplotypes or diplotypes with the susceptibility to keloid scarring in Polish patients.

Imiquimod to prevent keloid recurrence postexcision: A systematic review and meta-analysis

Imiquimod 5% cream, an immune response modifier capable of inducing IFN-α, TNF-α, and interleukins 1, 6, and 8. It was approved for use in the management of genital and perianal warts and soon embraced as a method to diminish the recurrence of keloids postexcision. A previous meta-analysis included four studies. This meta-analysis is part of a larger systematic review project on the effect of moisturizers on scars. It was conducted following an a priori protocol and the guidance of the Joanna Briggs Institute. Databases searched included PubMed, CINAHL, Embase, and Web of Science. After screening and critical appraisal, subgroup meta-analysis on excision method and location of the keloid was conducted using the Miller approach for proportional meta-analysis and a random effects model. Seven studies, including 77 participants and 82 keloids were included. Meta-analysis revealed a recurrence rate of 39% (95% CI = 8.474.4%; I² = 87.5%) following application of Imiquimod postexcision. The use of primary excision or tangential excision did not alter the outcome. For analysis based on the location of the keloid scar, earlobe keloids had a recurrence rate of 5.4% (95% CI = 0-21.7%; I² = 52.9%). For keloids excised from other areas (predominantly on the trunk) recurrence rate was higher, at 76.8% (95% CI = 36.1-100%). For keloids, Imiquimod application postexcision results in highly variable recurrence rates. There is very low certainty in the effect of Imiquimod and it therefore is not recommended as a treatment option.

A Novel Radiotherapy Approach for Keloids with Intrabeam

Background

Keloids are hard nodules or plaques formed by excessive proliferation of connective tissue. Radiotherapy, widely used in various benign and malignant skin diseases, is an effective treatment for keloids. This work evaluates Intrabeam photon radiotherapy in the management of keloids.

Methods

Fourteen patients who have undergone Intrabeam radiotherapy for a total of 15 sites of keloids were followed up. Twelve cases were first onset and the other two had recurrent diseases. Thirteen patients underwent surgical resection of keloids before radiotherapy. One relapsing patient received only 2 rounds of radiation therapy as she could not be reoperated. Radiotherapy was divided into 2 sessions on days 0 and 3 after surgery. The dose was 4 or 5 Gy each time for 3 min 14 s to 12 min 1 s. In addition, we compared our data to the recurrence of keloids in fourteen patients who had previously been exposed to electron beam using conventional accelerators.

Results

We analyzed the treatment for adverse reactions and recurrence. In the Intrabeam group, one patient developed superficial skin ulcers a month after treatment. No one experienced wound rupture, bleeding, infection, skin contractures, or obvious hyperpigmentation. None of the fourteen cases showed any recurrence so far after on median 22.5 months of follow-up. Five patients in the electron beam group relapsed 3 to 10 months after treatment.

Conclusion

Here, Intrabeam photon radiotherapy was shown to be an effective treatment for keloid scars and it is therefore recommended for management of this disease.