The Cellular Response of Keloids and Hypertrophic Scars to Botulinum Toxin A: A Comprehensive Literature Review

Investigating the impact of botulinum toxin type a on the migration of normal human dermal fibroblasts: An in vitro wound healing assay

BACKGROUND

Botulinum toxin A (BoNT-A) is widely utilized in the management of hypertrophic and keloid scars. One proposed mechanism for scar prevention involves the inhibition of fibroblast migration in scars by BoNT-A. However, the data regarding the effect of BoNT-A on the migration of normal human dermal fibroblasts (NHDF) is limited.

OBJECTIVES

The aim of this study was to investigate the inhibitory effect of different types and dilutions of BoNT-A on the migration of NHDF.

METHODS

In vitro scratch wound assay, NHDF cells were cultured, incubated, and subjected to scratching using a sterile tip. Subsequently, the scratched NHDF monolayer was treated with different types of BoNT-A, including onabotulinumtoxinA (ONA), incobotulinumtoxinA (INCO), prabotulinumtoxinA (PRABO), or letibotulinumtoxinA (LETI), at varying concentrations of 10, 20, 25, 40, 50, and 100 units/milliliter (U/mL). Additionally, abobotulinumtoxinA (ABO) was administered at concentrations of 33, 50, 66, 71, 100, 150, 300, and 500 U/mL. Normal saline solution (NSS) served as a negative control. The extent of NHDF migration was evaluated by comparing each dilution of BoNT-A with the controls using high-content imaging at the 48-h time point. Furthermore, the viability of the of NHDF was assessed.

RESULTS

The concentrations of 25, 40, and 50 U/mL of ONA (p < 0.001) and 25 U/mL of LETI (p < 0.05) demonstrated significantly inhibited NHDF migration in comparison to the control group. Conversely, all dilutions of PRABO, INCO, and ABO exhibited comparable NHDF migration to that of the control group. Regarding NHDF viability, no significant decrease was observed across any of the BoNT-A types and dilutions.

CONCLUSION

Different types and dilutions of BoNT-A demonstrated variable inhibitory effects on NHDF migration in vitro. The selection of BoNT-A formulation may significantly impact the clinical outcome of scar prevention related to fibroblast migration.

New and Future Developments in Neurotoxins

BACKGROUND

There are 7 known serotypes of botulinum neurotoxins (A through G). Currently, commercially available toxins are those in serotypes A and B. This paper will discuss new toxins on the horizon, developments in prolonging and shortening the duration of outcomes, and novel therapeutic indications on the horizon.

OBJECTIVE

To provide insight into new toxins and new therapeutic modalities surrounding toxins on the horizon.

METHODS

The authors have reviewed the relevant literature and shared their insights and opinions as to future developments in toxin research and potential clinical applications.

CONCLUSION

Botulinum neurotoxin type E's faster onset and shorter duration of effect represent true clinical differentiators. Future development of botulinum neurotoxin type E for aesthetic and therapeutic uses will be in areas where fast onset and short duration of effect are desirable. Current challenges with neuromodulators include the need for frequent treatments and lack of reversal agents. Agents to address both challenges and novel indications, including inhibition of melanogenesis, are being developed.

Effectiveness of microneedle fractional radiofrequency combined with transcutaneous delivery of botulinum toxin in the management of post-acne scars

BACKGROUND

Post-acne scars are a common sequela of acne, especially prevalent among young people. Delayed treatment not only affects self-perception of beauty but also affects the mental health of patients.

OBJECTIVE

This study aims to investigate the clinical efficacy of microneedle fractional radiofrequency (MFR) combined with botulinum toxin A (BoNT/A) in managing post-acne scars.

METHODS

This retrospective study involved 63 adult patients with post-acne scars, divided into two groups: group 1 (n = 30) and group 2 (n = 33). Group 1 received treatment with MFR combined with transcutaneous delivery of BoNT/A, whereas group 2 received treatment with MFR alone. The study observed the clinical outcomes in both groups.

RESULTS

Based on experimental analysis, the combination of MFR with transcutaneous delivery of BoNT/A demonstrated superior clinical efficacy compared with group 2. There were no significant differences in baseline data or treatment-related pain and adverse reactions between the two groups. However, group 1 exhibited a higher effectiveness rate, lower ECCA score after treatment, higher satisfaction levels, and statistically significant differences compared to group 2.

CONCLUSION

MFR combined with transcutaneous delivery of BoNT/A represents an effective and safe alternative for treating acne scars with minimal side effects and complications.

SUMMARY STATEMENT

Post-acne scars are a common sequela of acne and combination therapy proves beneficial. Microneedle fractional radiofrequency (MFR) combined with transcutaneous delivery of BoNT/A can be considered an effective and safe alternative for the treatment of acne scars with minimal side effects and complications. It works together through microneedles, radiofrequency, and botulinum toxin. MFR combined with transcutaneous delivery of BoNT/A is based on the direct action of MFR on acne scars and the use of microneedle to create a transient skin microchannel, facilitating BoNT/A penetration into the skin.

Using Neuromodulators to Improve Scar Formation, Keloids, Rosacea, and Antiaging

BACKGROUND

Botulinum toxin A (BoNT-A) treatment has many uses in dermatology. Its mechanism of action and long-term effects for scar formation, rosacea, and antiaging are still being investigated.

OBJECTIVE

To conduct a literature review on BoNT-A to further investigate its use in scar formation, rosacea, and antiaging.

METHODS

A literature review was conducted using PubMed on botulinum toxin treatment for scar formation, rosacea, and antiaging. Studies discussing the toxin mechanism of action and treatment algorithm were included. The authors also provided their personal experience in BoNT-A use for these 3 conditions.

RESULTS

The mechanism of action of Botulinum toxin A in improving scar formation, rosacea, and antiaging is now better understood. While it is effective in the short term, little is still known about how frequently treatment needs to be repeated and if there are any long-term effects.

CONCLUSION

While in vitro studies have supporting evidence on the mechanism of action of BoNT-A on scar formation, rosacea, and antiaging, further studies are needed to identify long-term treatment effects.

Comprehensive Insights into Keloid Pathogenesis and Advanced Therapeutic Strategies

Keloid scars, characterized by abnormal fibroproliferation and excessive extracellular matrix (ECM) production that extends beyond the original wound, often cause pruritus, pain, and hyperpigmentation, significantly impacting the quality of life. Keloid pathogenesis is multifactorial, involving genetic predisposition, immune response dysregulation, and aberrant wound-healing processes. Central molecular pathways such as TGF-β/Smad and JAK/STAT are important in keloid formation by sustaining fibroblast activation and ECM deposition. Conventional treatments, including surgical excision, radiation, laser therapies, and intralesional injections, yield variable success but are limited by high recurrence rates and potential adverse effects. Emerging therapies targeting specific immune pathways, small molecule inhibitors, RNA interference, and mesenchymal stem cells show promise in disrupting the underlying mechanisms of keloid pathogenesis, potentially offering more effective and lasting treatment outcomes. Despite advancements, further research is essential to fully elucidate the precise mechanisms of keloid formation and to develop targeted therapies. Ongoing clinical trials and research efforts are vital for translating these scientific insights into practical treatments that can markedly enhance the quality of life for individuals affected by keloid scars.

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Acne-induced pathological scars: pathophysiology and current treatments

Acne is a common chronic inflammatory dermatosis that can lead to pathological scars (PSs, divided into hypertrophic scars and keloids). These kinds of abnormal scars seriously reduce the quality of life of patients. However, their mechanism is still unclear, resulting in difficult clinical prevention, unstable treatment effects and a high risk of recurrence. Available evidence supports inflammatory changes caused by infection as one of the keys to abnormal proliferation of skin fibroblasts. In acne-induced PSs, increasing knowledge of the immunopathology indicates that inflammatory cells directly secrete growth factors to activate fibroblasts and release pro-inflammatory factors to promote the formation of PSs. T helper cells contribute to PSs via the secretion of interleukin (IL)-4 and IL-13, the pro-inflammatory factors; while regulatory T cells have anti-inflammatory effects, secrete IL-10 and prostaglandin E2, and suppress fibrosis production. Several treatments are available, but there is a lack of combination regimens to target different aspects of acne-induced PSs. Overall, this review indicates that the joint involvement of inflammatory response and fibrosis plays a crucial role in acne-induced PSs, and also analyzes the interaction of current treatments for acne and PS.

Asiatic acid-entrapped transfersomes for the treatment of hypertrophic scars: In vitro appraisal, bioactivity evaluation, and clinical study

Non-invasive treatment options for hypertrophic scars (HTS) are limited, and treating HTS remains challenging due to their unappealing appearance and associated social stigma. In this work, a novel transfersomal system named Asiatic acid-entrapped transfersomes (AATs) was prepared. AATs were evaluated for their skin permeability, anti-inflammatory activity, and other characteristic parameters to determine the most promising formulation. Asiatic acid-entrapped transfersomal gel (AATG), which was obtained by incorporating the lead AATs in a gel base, underwent testing in an 8-week, double-blind, placebo-controlled, split-skin clinical study. The net skin elasticity (R5), melanin index (MI), and skin surface hydration were analyzed employing Cutometer®, Mexameter®, and Corneometer®, respectively, in order to evaluate the effectiveness of the developed AATG. AATs exhibited vesicular sizes and zeta potential values within the range of (27.15 ± 0.95 to 63.54 ± 2.51 nm) and (-0.010 to -0.129 mV), respectively. TW80AAT gave the highest %EE (90.84 ± 2.99%), deformability index (101.70 ± 11.59 mgs-1), permeation flux at 8 h (0.146 ± 0.005 mg/cm2/h), and anti-inflammatory activity (71.65 ± 1.83%). The clinical study results of AATG indicated no adverse skin reactions. Furthermore, product efficacy tests demonstrated a significant reduction in MI and an increase in net skin elasticity at 2, 4, and 8 weeks. These pilot study outcomes support the effectiveness of the AATG.

Comparison research on the therapeutic effects of botulinum toxin type A and stromal vascular fraction gel on hypertrophic scars in the rabbit ear model

BACKGROUND AND OBJECTIVES

Botulinum toxin type A (BTA) is often used for wrinkles and muscle convulsive diseases due to its blocking of the transmission of nerve impulses. Stromal vascular fraction gel (SVF-gel) prepared from adipose tissue has novel effects on skin depression and poor texture. Both BTA and SVF-gel are proved to possess anti-scar potential. This study aimed to assess and compare their therapeutic effects on hypertrophic scars.

MATERIALS AND METHODS

The rabbit ear scar model was established and treated with BTA and SVF-gel, alone or in combination. Gross evaluation using Manchester Scar Scale (MSS) was conducted immediately, 4 and 8 weeks after initial treatment. After tissue sample harvest, histological and Western blot analyses were performed.

RESULTS

All the treatments alleviated scar hyperplasia in different degrees by inhibiting fibroblast activation (Ki-67, α-SMA), tissue inflammation (CD45, IL-1β) and the transforming growth factor-β1 (TGF-β1)/Smad3 pathway. Despite an excellent anti-inflammatory effect, improvement of scar appearance and pathological characteristics in SVF-gel-contained groups was not as good as that in BTA-only group, which might be related to the retention of M2-type macrophages (CD163 +) and partial maintenance of TGF-β1 expression.

CONCLUSION

Our data suggest that BTA has better anti-scar efficacy than SVF-gel, and the combination of these two treatments shows no obvious combinatorial effect.

Pharmacotherapy of urethral stricture

Urethral stricture is characterized by the chronic formation of fibrous tissue, leading to the narrowing of the urethral lumen. Despite the availability of various endoscopic treatments, the recurrence of urethral strictures remains a common challenge. Postsurgery pharmacotherapy targeting tissue fibrosis is a promising option for reducing recurrence rates. Although drugs cannot replace surgery, they can be used as adjuvant therapies to improve outcomes. In this regard, many drugs have been proposed based on the mechanisms underlying the pathophysiology of urethral stricture. Ongoing studies have obtained substantial progress in treating urethral strictures, highlighting the potential for improved drug effectiveness through appropriate clinical delivery methods. Therefore, this review summarizes the latest researches on the mechanisms related to the pathophysiology of urethral stricture and the drugs to provide a theoretical basis and new insights for the effective use and future advancements in drug therapy for urethral stricture.

Anti-Fibrotic Effects of RF Electric Currents

Hypertrophic scars and keloids are two different manifestations of excessive dermal fibrosis and are caused by an alteration in the normal wound-healing process. Treatment with radiofrequency (RF)-based therapies has proven to be useful in reducing hypertrophic scars. In this study, the effect of one of these radiofrequency therapies, Capacitive Resistive Electrical Transfer Therapy (CRET) on biomarkers of skin fibrosis was investigated. For this, in cultures of human myofibroblasts treated with CRET therapy or sham-treated, proliferation (XTT Assay), apoptosis (TUNEL Assay), and cell migration (Wound Closure Assay) were analyzed. Furthermore, in these cultures the expression and/or localization of extracellular matrix proteins such as α-SMA, Col I, Col III (immunofluorescence), metalloproteinases MMP1 and MMP9, MAP kinase ERK1/2, and the transcription factor NFκB were also investigated (immunoblot). The results have revealed that CRET decreases the expression of extracellular matrix proteins, modifies the expression of the metalloproteinase MMP9, and reduces the activation of NFκB with respect to controls, suggesting that this therapy could be useful for the treatment of fibrotic pathologies.

Concentration-Dependent Inhibition of Hypertrophic Scar Formation by Botulinum Toxin Type A in a Rabbit Ear Model

BACKGROUND

Hypertrophic scar (HS), as a disappointing result of wound healing, adversely affects the patient, both physically and psychologically. Botulinum toxin type A (BTXA) has been revealed to prevent and improve HS. We conducted this study to assess the effect of different BTXA concentrations on inhibiting HS in a rabbit ear model.

METHODS

Eight healthy New Zealand long-eared rabbits were included in the experiment for modeling. Four wounds of 1 cm in diameter were created on both ears, which separately received an injection of a given BTXA concentration immediately after surgery. On postoperative days 40, scar tissue was obtained and subjected to hematoxylin and eosin (HE) staining for the hypertrophic index (HI) and immunohistochemical staining for CD31, Ki67, and transforming growth factor-beta 1 (TGF-β1) expression. The HI was assessed for scar proliferation, and CD31 and Ki67 expression were used to assess the effect of BTXA on angiogenesis and fibroblast proliferation, respectively.

RESULTS

All rabbits healed well without infection or mortality. From the HE staining, the HI showed a significant decrease with increasing BTXA concentration (p < 0.05). BTXA also inhibited angiogenesis and TGF-β1 expression in a concentration-dependent manner, with significant differences between the groups (p < 0.05). BTXA inhibited fibroblast proliferation with increasing BTXA concentration. However, there was no significant difference between the 0.5 U/0.1 ml and 0 U/0.1 ml groups (p > 0.05).

CONCLUSION

Immediate postoperative BTXA injection inhibited angiogenesis, fibroblast proliferation, and TGF-β1 expression in a concentration-dependent manner, thus suppressing HS formation in rabbit ears.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/journal/00266 .

Microneedle delivery of botulinum toxin type A combined with hyaluronic acid for the synergetic management of multiple sternal keloids with oily skin: A retrospective clinical investigation

BACKGROUND

For the treatment of sternal keloids, corticosteroid therapy has side effects including abnormal sebum secretion and acne. Relapse of keloids is common after corticosteroid injection in patients with oily skin. To reduce side effects and keloid recurrence, we used a combination of botulinum toxin type A (BTX-A) and hyaluronic acid (HA) as synergetic management for multiple sternal keloids in patients with oily skin.

METHODS

In total, 58 patients with multiple sternal keloids who received monthly steroid injections were retrospectively included. Thirty-two patients in the intervention group received an additional injection of BTX-A/HA on the same day as the first injection of the steroid, while the remaining 26 patients were treated as the control group. At baseline and follow-up visits, sebum production and transepidermal water loss (TEWL) were assessed as primary outcomes, and the Vancouver Scar Scale (VSS) score, keloid recurrence, visual analog scale (VAS) score, and patient satisfaction were assessed as secondary outcomes.

RESULTS

In the control group, average sebum production and TEWL were increased to 132% and 104% of baseline, respectively, at the 24-week follow-up. In the intervention group, average sebum production and TEWL reached nadir at the 8-week follow-up and then increased to 96% and 91% of baseline, respectively, at the 24-week follow-up. Sternal keloid relapse was observed in 88.5% of the patients in the control group and none of the patients in the intervention group. The total VSS score at 24 weeks was 11.04 ± 0.14 and 8.93 ± 0.26 (p < 0.001) in the control group and intervention group, respectively, and the VAS score was 75 ± 5.10 and 19.14 ± 3.80 (p < 0.001) in the control group and intervention group, respectively. Higher patient satisfaction was reported in the intervention group.

CONCLUSIONS

Microneedle delivery of BTX-A/HA decreases sebum production while improving skin barrier function. Thus, this combined therapy can relieve the side effects of corticosteroid therapy and reduce keloid recurrence.

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.

Efficacy of Botulinum Toxin A for Scar Prevention After Breast Augmentation: A Randomized Double-Blind Intraindividual Controlled Trial

BACKGROUND

Botulinum toxin A benefits postsurgical scar prevention by reducing wound edge tension and inhibiting in vitro scar tissue fibrosis.

OBJECTIVE

To investigate the efficacy of botulinum toxin Type A (BTX) in improving inframammary scar appearance after primary breast augmentation.

MATERIALS AND METHODS

A prospective, double-blinded, randomized controlled trial was performed with 27 participants receiving primary augmentation mammoplasty with inframammary incisions. After skin closure, intradermal injections of BTX were administered to 1 (treated) side of the inframammary incision. The contralateral side was the control. Scars were evaluated at 3 months, 6 months, and 9 months using the Patient and Observer Scar Assessment Scale and multispectral imaging analysis.

RESULTS

Overall, 22 patients completed the study. There were no significant subjective differences between the treated and control sides except the patient's treated side had significantly higher scores than the control side at 9 months. The treated side showed significantly smaller scar widths at 6 months and 9 months (p < .001) and better scar surface textures at 9 months (p = .003) than the control side.

CONCLUSION

Subjectively, intradermal BTX injection immediately after breast augmentation skin closure caused no significant differences. Objectively, scar width and texture significantly improved at 6 months and 9 months.

Emerging off-label esthetic uses of botulinum toxin in dermatology

Botulinum toxin is a neurotoxic protein produced by Clostridium botulinum, the bacterium responsible for botulism. Botulinum toxin was first used for therapeutic indications in the 1970s for the treatment of strabismus. With greater understanding of its underlying physiology and safety profile, the use of botulinum toxin has now expanded to a range of cosmetic and medical indications. We performed a systematic review of current literature on the applications of botulinum toxin on off-label esthetic uses. Electronic databases were searched for original published studies including randomized trials, observational or cohort studies, as well as relevant case reports. To add to the body of evidence, our review summarizes and synthesizes key study characteristics, results, and level of evidence for each use case. Although the body of evidence remains weak, there is increasing support for the use of botulinum toxin in emerging off-label esthetic uses of botulinum toxin in dermatology.

The Efficacy and Safety of Botulinum Toxin Injections in Preventing Postoperative Scars and Improving Scar Quality: A Systematic Review and Meta-Analysis

BACKGROUND

Scars exposed on the body surface lead to a large psychological burden on patients. However, no satisfactory scar treatments exist. Botulinum toxin type A is a neurotoxin that has been widely applied in the plastic and cosmetic surgery field. The purpose of this meta-analysis was to assess the efficacy and safety of botulinum toxin in scar management.

METHODS

PubMed, the Cochrane Library, EMBASE, MEDLINE, and Web of Science were searched for randomized controlled trials that evaluated the efficacy of botulinum toxin injections in preventing postoperative scars and improving scars quality and were published prior to Dec. 29, 2020. The outcome indicators were the visual analog scale score, Vancouver scar scale score, Stony Brook scar evaluation scales score, scar width, patient self-assessment results, and complications.

RESULTS

Seventeen randomized controlled trials with a total of 633 cases were identified in this meta-analysis. The quantitative synthesis results showed that compared with the control group, the botulinum toxin group had a significantly lower VSS score (MD = -0.97, 95%CI = -1.56 to -0.39, p = 0.001), higher VAS score (MD = 1.26, 95%CI = 1.04 to 1.47, p < 0.00001), thinner scar width (MD = -0.25, 95%CI = -0.37 to -0.12, p < 0.0001) and higher patient satisfaction (RR = 3.38 95%CI = 1.45 to 7.89, p = 0.005). There were no significant differences between the two groups in the number of adverse events.

CONCLUSIONS

This meta-analysis demonstrated that botulinum toxin injections can significantly improve cosmetic appearance and postoperative scar quality. At the therapeutic dose, no significant complications were observed, indicating that botulinum toxin injections are safe.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Treatment of Wound Healing with Sequential Therapy to Accelerate Recovery and Inhibit Scar Hyperplasia: A Case Report

Study Design/Patients and Methods

A 19-year-old male was reported to have a postoperative facial trauma suture as a result of being involved in a car accident. Red light-emitting diode (LED) therapy (20 min, 96 J/cm², 633 nm), Botulinum Toxin Type A 36 IU injection, BroadBand Light and Er:YAG laser at various stages of wound healing were applied as the sequential therapy.

Results

Since the correction was promptly apparent and acceptable, the treatment proved secure and efficacious for repairing wound healing.

Conclusion

Clinically sequential therapy has demonstrated marked improvement in our case. Scar sequential therapy may offer a new strategy for wound healing recovery.

Emerging and Novel Therapies for Keloids: A compendious review

Keloids are abnormal fibroproliferative scars with aggressive dermal growth expanding beyond the borders of the original injury. Different therapeutic modalities, such as corticosteroids, surgical excision, topical silicone gel sheeting, laser therapy, cryotherapy, photodynamic therapy and radiotherapy, have been used to treat keloids; however, none of these modalities has proven completely effective. Recently, researchers have devised several promising anti-keloid therapies including anti-hypertensive pharmaceuticals, calcineurin inhibitors, electrical stimulation, mesenchymal stem cell therapy, microneedle physical contact and ribonucleic acid-based therapies. The present review summarises emerging and novel treatments for keloids. PubMed^® (National Library of Medicine, Bethesda, Maryland, USA), EMBASE (Elsevier, Amsterdam, Netherlands) and Web of Science (Clarivate Analytics, Philadelphia, Pennsylvania, USA) were searched for relevant literature published between January 1987 to June 2020. A total of 118 articles were included in this review. A deeper understanding of the molecular mechanisms underlying keloid scarring pathogenesis would open further avenues for developing innovative treatments.

Effect of Artesunate Combined With Fractional CO2 Laser on the Hypertrophic Scar in a Rabbit Model

BACKGROUND AND OBJECTIVES

Hypertrophic scar (HS), a common complication in wound healing, is characterized by the disarrangement of collagen, fibers, and extracellular matrix. Artesunate (ART) can inhibit the abnormal formation of fibroblasts and collagens. Fractional CO2 laser (FCO2 L) can facilitate tissue remodeling and the absorption of drugs into ablative microthermal columns in HS. So far, no research has investigated the efficacy of ART combined with an FCO2 L in treating HS. To investigate the theoretical basis and clinical significance of this combination, we established a rabbit model of HS to observe the change in the expression of transforming growth factor β1 (TGF-β1) and proliferating cell nuclear antigen (PCNA).

STUDY DESIGN/MATERIALS AND METHODS

Forty New Zealand white rabbits were randomly divided into four groups: control group, ART group, FCO2 L group, and ART + FCO2 L (combination) group. Four wounds were surgically established in the ear of each rabbit and allowed to develop into HS. ART (20 μL/cm2 ) was injected in ART and combination groups, and FCO2 L (combo mode, deep energy:10m J, super energy: 50 mJ) in FCO2 L and combination groups on the 28th day after HS occurred. Three rounds of treatment were applied (once every 14 days). HS samples were measured by hematoxylin and eosin staining, Van Gieson staining, immunohistochemistry, and Western blot analysis on the 70th day.

RESULTS

The morphological and histopathological changes in HS were significant. HSs were smoother and smaller and the collagen fibers were thinner and less disordered in the combination group than those in ART and FCO2 L groups. Meanwhile, the hypertrophic index (HI), fiber density (NA), and collagen fiber content (AA) were lower in the combination group (1.54 ± 0.15, 3.30 ± 0.22, 30.37 ± 1.41%) than in the ART group (2.51 ± 0.22, 4.69 ± 0.16, 44.68 ± 2.30%) and FCO2 L group (1.99 ± 0.14, 4.13 ± 0.12, 37.74 ± 1.38%) (P < 0.01). Additionally, the expressions of TGF-β1 and PCNA protein were suppressed in the ART group (0.30 ± 0.03, 0.25 ± 0.03) and FCO2 L group (0.35 ± 0.03, 0.32 ± 0.05), and the suppression was more significant in the combination group(0.07 ± 0.02, 0.07 ± 0.02) (P < 0.01).

CONCLUSIONS

The combination of ART and FCO2 L can effectively reduce HS in the rabbit model. This is the first report about this combination in the treatment of HS. A novel treatment is expected to be based on our findings. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Alternative Clinical Indications of Botulinum Toxin

Botulinum toxin type A (BoNTA) is a powerful neurotoxin that inhibits acetylcholine release from presynaptic vesicles. The potency and safety profile of BoNTA grant the toxin vast therapeutic potential. It has been used off-label for a variety of dermatologic conditions. This review aims to analyze published literature regarding the benefits and risks of the off-label use of BoNTA beyond facial lines, including eccrine hidrocystomas, enlarged pores, keloids and hypertrophic scars, hidradenitis suppurativa, hyperhidrosis, masseter muscle hypertrophy, and salivary gland hypertrophy, among others. A MEDLINE search from January 2000 to December 2019 was conducted on the off-label uses of botulinum toxin in dermatology.

Prevention of scar hyperplasia in the skin by conotoxin: A prospective review

Scars are often considered to be skin problems that affect beauty. The tension acting on the edge of the wound is the main factor causing the scar hyperplasia. At present, the clinical use of botulinum toxin A (BTX-A) around the wound to cause transient muscle paralysis reduce the muscle movement around the wound and wound tension to prevent scar hyperplasia during wound healing. But the use of BTX-A to prevent scarring requires the use of a syringe. The syringe can cause trauma and pain when it pricks the skin for BTX-A injection. The conotoxin which is secreted by the poison glands on the inside of the venom tube and capsule of the snail provides a simple and effective way to prevent skin scar hyperplasia. We reviewed the classification of conotoxin, the conotoxin's mechanism of preventing scar hyperplasia, and the research direction of conotoxin in the future and provided reference for promoting the application of conotoxin in preventing skin scar hyperplasia.

BTXA regulates the epithelial-mesenchymal transition and autophagy of keloid fibroblasts via modulating miR-1587/miR-2392 targeted ZEB2

Keloids are very resistant to treatment in dermatology and plastic surgical practice. The present study aimed to explore the underlying mechanism of botulinum toxin A (BTXA) treated human skin keloid fibroblasts (HSFBs) proving some new insights into keloids treatment. Expression of miR-1587 and miR-2392 were significantly down-regulated in keloid tissues and HSFBs, while the ZEB2 was a target of both and up-regulated in keloid tissues and HSFBs compared with the normal controls. BTXA could significantly increase the expression of miR-1587 and miR-2392 but decrease the expression of ZEB2. BTXA could significantly inhibit the proliferation, cell cycle, and migration and promote apoptosis and autophagy of HSFBs; however, miR-1587 and miR-2392 inhibitors could reverse these effects of BTXA on HSFBs. Silencing ZEB2 could significantly attenuate the effects of miR-1587 and miR-2392 inhibitors in promoting cell proliferation and migration and suppressing apoptosis and autophagy of HSFBs after treating with BTXA. BTXA could suppress the proliferation and migration and promote apoptosis and autophagy of HSFBs via modulating miR-1587/miR-2392 targeted ZEB2.

Keloids: a review of therapeutic management

Keloid scar formation arises from a disorganized fibroproliferative collagen response that extends beyond the original wound margins because of excessive production of extracellular matrix (ECM). Despite treatment options for keloid scars including medical and surgical therapies, such as intralesional steroid injection and surgical excision, the recurrence rate remains high. Herein we consolidate recently published narrative reviews, systematic reviews, and meta-analyses to provide an overview of updated treatment recommendations for keloidal scar formation. PubMed search engine was used to access the MEDLINE database to investigate updates regarding keloid incidence and treatment. More than 100 articles were reviewed. Keloid management remains a multimodal approach. There continues to be no gold standard of treatment that provides a consistently low recurrence rate; however, the increasing number of available treatments and synergistic combinations of these treatments (i.e., laser-based devices in combination with intralesional steroids, or 5-fluorouracil (5-FU) in combination with steroid therapy) is showing favorable results. Future studies could target the efficacy of novel treatment modalities (i.e., autologous fat grafting or stem cell-based therapies) for keloid management. This review article provides updated treatment guidelines for keloids and discusses insight into management to assist patient-focused, evidence-based clinical decision making.

Botulinum toxin type A versus 5-Fluorouracil in treatment of keloid

Most therapeutic approaches for keloids remain clinically unsatisfactory. In the last years, intralesional botulinum toxin-A (IL BTX-A) was proposed for treatment of keloids. Our aim of the study was to compare the clinical efficacy of IL BTX-A and IL 5-Fluorouracil (IL 5-FU) in treatment of keloids. A total of 50 patients with keloids were included in the study, 22 patients (with 26 keloids) were treated with IL BTX-A monthly for up to 6 months and other 22 patients (with 27 keloids) were treated with IL 5-FU weekly for up to 6 weeks, while the remaining 6 patients, each having multiple keloids, were treated with both IL BTX-A for some lesions (8 keloids) and IL 5-FU for their remaining lesions (8 keloids). The clinical improvement was assessed according to flattening of the lesions. Side effects were recorded. A significantly better therapeutic response of keloids was detected after IL BTX-A than IL 5-FU (P = 0.041). IL BTX-A achieved excellent and good flattening of the lesions (58.8% and 20.6%) compared to (31.4% and 17.1%) after IL 5-FU, respectively. In BTX-A treated group, there was no statistically significant difference between the clinical response in small lesions compared to medium and large ones (P = 0.476). While in 5-FU treated group, small and medium lesions showed significantly better response than larger ones (P = 0.009). IL BTX-A caused fewer side effects than IL 5-FU, less pain, itching, no hyperpigmentation and less recurrence. Both IL BTX-A and IL 5-FU showed positive results in treatment of keloids. However, IL BTX-A showed higher clinical efficacy even in large size keloids with less side effects.

Efficacy and safety of Nd:YAG laser alone compared with combined Nd:YAG laser with intralesional steroid or botulinum toxin A in the treatment of hypertrophic scars

The aim of this study is to evaluate the efficacy and safety of Nd:YAG laser alone or in combination with intralesional injection of botulinum toxin type A or intralesional injection of steroid in treatment of hypertrophic scars. This study included 45 patients with hypertrophic scars who were randomly divided into three equal groups. All participants received 4 sessions of Nd:YAG laser at 4-week intervals. Immediately after the laser treatment, patients in group II were assigned to intralesional triamcinolone acetonide, and those in group III were assigned to intralesional botulinum toxin type A. All patients were followed up monthly for 3 months after the last session for any recurrence, or side effects. Clinical evaluation of the cases was done by Vancouver Scar Scale. Hypertrophic scars in the three groups showed a significant improvement (p < 0.001) compared with before treatment in all variables (except for pigmentation) and also a significant improvement in pruritus, pain, and patient relief. The highest percentage of improvements was seen in patients treated with Nd:YAG laser combined with intralesional steroid in all variables according to Vancouver Scar Scale. The degree of improvement was negatively correlated with the patients' age. The three treatment modalities were effective, safe with minimal side effects. Nd:YAG laser followed by intralesional injection of Triamcinolone acetonide had the highest percentage of Vancouver Scar Scale reduction. Combination therapy of Nd:YAG laser with intralesional injection of either Triamcinolone acetonide or Botox revealed better results than using Nd:YAG as a single therapeutic modality for HTS.

Application of Botulinum Neurotoxin in Male Sexual Dysfunction: Where Are We Now?

INTRODUCTION

Botulinum neurotoxin (BoNT) is a recognized therapeutic agent of modern medical care, routinely used to treat medical conditions affecting a variety of organ systems including the musculoskeletal, integumentary, and urological domains. Ongoing research is exploring BoNT's potential role as a therapeutic agent for a variety of male sexual pathologies.

OBJECTIVE

To review and analyze the literature regarding BoNT as a treatment option for male sexual dysfunction.

METHODS

A PubMed search was performed for English-language articles in peer-reviewed journals between 1970 and 2019 (with one article from 1897). Relevant articles referenced within these texts were also included. One article did not have an accompanied English full-text available. The following search terms were used: "Botox", "Botulinum toxin", "Botulinum toxin A", "Onabotulinum A", "Abobutlinum A", "BoNT", "BoNT-A", "Male sexual health", "Male sexual pathology", "Peyronie's disease", "Premature ejaculation", "Scrotal Pain", "Penile Retraction", "Scrotox", "Erectile Dysfunction", and "Botox in Urology".

RESULTS

There is interest in the potential role of BoNT in the treatment of male sexual pathologies. We identified studies that used BoNT to treat chronic scrotal content pain, premature ejaculation, erectile dysfunction, Peyronie's disease, penile retraction, and more. However, despite preclinical/clinical data indicating some potential efficacy and safety in these settings, a lack of robust clinical trial data has resulted in no current Food and Drug Administration-approved indications for the use of BoNT in the treatment of male sexual pathology. As a result, much of the current use of BoNT by today's providers is "off-label," and ongoing clinical trials aim to further elucidate the potential role of this therapeutic agent.

CONCLUSION

Current data suggest that BoNT could have a potential role as a treatment option for certain types of male sexual pathologies. However, more randomized controlled trial data regarding its long-term safety and efficacy are necessary before a widespread clinical adoption can take place. Reddy AG, Dick BP, Natale C, et al. Application of Botulinum Neurotoxin in Male Sexual Dysfunction: Where Are We Now?. J Sex Med 2021;9:320-330.

Efficacy of Botulinum Toxin Type A in Improving Scar Quality and Wound Healing: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Botulinum toxin type A-induced "chemoimmobilization" has long been utilized for improved scar quality and wound healing; however, current evidence is limited to small studies, and evidence-based information is inadequate to make well-informed decisions.

OBJECTIVES

The purpose of this study was to evaluate the efficacy of botulinum toxin type A (BTA) to improve scars and wound healing.

METHODS

The authors searched databases, including Pubmed, Embase, and Cochrane Library, to identify randomized clinical trials (RCTs) that compared outcomes of surgical scars and wounds treated with BTA vs those treated with blank or placebo controls. The Visual Analog Scale, Vancouver Scar Score, scar width, and reported patient satisfaction were utilized in evaluating outcomes. Adverse events were also recorded.

RESULTS

Eleven RCTs involved a total of 486 cases (374 patients). Quantitative synthesis suggested that compared with the control group, patients in the BTA treatment group had significantly higher Visual Analog Scale scores (mean difference [MD] = 1.30, 95% confidence interval [CI]: 1.05 to 1.55), lower Vancouver Scar Scores (MD = -1.62, 95% CI: -2.49 to -0.75, P = 0.0003), and thinner scars (MD = -0.15, 95% CI: -0.20 to -0.11, P < 0.00001). Patient satisfaction was higher in the BTA group than in the control group (risk ratio: 1.25, 95% CI: 1.06 to 1.49, P = 0.01). Trivial adverse events were reported.

CONCLUSIONS

This meta-analysis of RCTs provides reliable evidence that BTA injection is superior to placebo or blank control group in improving scar quality and wound healing in the face and neck for Asians, and negative outcomes for BTA treatment in these patients include only trivial adverse events. However, inadequate evidence supports utilization of BTA in Caucasians for primary surgical scars or for scars in locations other than the face and neck. Further studies on the standardized injection regimen and technique of BTA are warranted for clinical practice.

LEVEL OF EVIDENCE: 1

Botulinum toxin type A suppresses pro-fibrotic effects via the JNK signaling pathway in hypertrophic scar fibroblasts

Hypertrophic scar is a dermal fibroproliferative disease characterized by the overproduction and deposition of extracellular matrix, and the hyperproliferation and enhanced angiogenesis of fibroblasts, along with their enhanced differentiation to myofibroblasts. Botulinum toxin type A shows potential for prevention of hypertrophic scar formation; however, its effectiveness in attenuating skin fibrosis and the related mechanism are unclear. In this study, human scar fibroblasts were cultured and stimulated with botulinum toxin type A, and the changes in fibroblast proliferation, migration, and protein expression of pro-fibrotic factors were evaluated with colorimetric, scratch, and enzyme-linked immunosorbent assays and western blotting, respectively. Botulinum toxin type A treatment decreased the proliferation and migration of human scar fibroblasts compared with those of untreated controls. Protein expression levels of pro-fibrotic factors (transforming growth factor β1, interleukin-6, and connective tissue growth factor) were also inhibited by botulinum toxin type A, whereas the JNK phosphorylation level was increased. Activation of the JNK pathway demonstrated the inhibitory effects of the toxin on human scar fibroblast proliferation and production of pro-fibrotic factors, suggesting that the suppressive effects of botulinum toxin type A are closely associated with JNK phosphorylation. Overall, this study showed that botulinum toxin type A has a suppressive effect on extracellular matrix production and scar-related factors in human scar fibroblasts in vitro, and that regulation of JNK signaling plays an important role in this process. Our results provide a theoretical basis, at the cellular level, for the therapeutic use of botulinum toxin type A.

Intralesional Injection of Botulinum Toxin Type A Compared with Intralesional Injection of Corticosteroid for the Treatment of Hypertrophic Scar and Keloid: A Systematic Review and Meta-Analysis

BACKGROUND The optimal treatment for hypertrophic scar and keloid remains controversial. Therefore, the aim of this systematic review and meta-analysis was to compare the effectiveness of intralesional injection of botulinum toxin type A compared with placebo and intralesional injection of corticosteroid compared with placebo in patients with hypertrophic scar and keloid. MATERIAL AND METHODS Six databases were searched using Medical Subject Headings (MeSH) keywords and included Web of Science, PubMed, EMBASE, the Cochrane Library, WanFang, and CNKI from their inception to March 1 2019, without language restriction. Randomized controlled trials (RCTs) and prospective controlled trials (PCTs) were identified that compared intralesional injection of botulinum toxin type A with placebo and corticosteroid with placebo in hypertrophic scar and keloid. The quality of controlled trials was assessed by the Newcastle-Ottawa Scale (NOS). RESULTS Comparison of intralesional botulinum toxin type A and corticosteroid showed significant differences in the Visual Analog Scale (VAS) (P<0.001) (WMD, -4.30; 95% CI, -4.44 to -4.16) and effective rate (P=0.012) (RR=0.82; 95% CI, 0.70-0.96). Intralesional injection of botulinum toxin type A compared with placebo showed significant differences in the VAS (P<0.001) (WMD, 1.41; 95% CI, 1.21-1.62), the width of scar (P=0.00) (WMD, -0.15; 95% CI, -0.19 to -0.10) and Vancouver Scar Scale (VSS) (P=0.003) (WMD, -0.69; 95% CI, -1.14 to -0.23). CONCLUSIONS Systematic review and meta-analysis showed that injection of intralesional botulinum toxin type A was more effective in the treatment of hypertrophic scar and keloid than injection of intralesional corticosteroid or placebo.

Keloid Formation due to Repetitive Mammographies

A keloid is the result of an abnormal wound healing response to a variety of skin injuries, characterized by a well-circumscribed, firm, irregular, mildly tender, and pink to purple hyperpigmented lump with a glossy surface. The present case reports on excessive formation of keloid due to repetitive mammographies causing symptomatic, cosmetically disturbing symptoms.

[What's new in interventional dermatology?]

This year, many publications have focused on understanding, avoiding and treating vascular complications when injecting fillers. New protocols for the use of hyaluronidase have shown their effectiveness in preventing skin necrosis or blindness after vascular embolism when injecting hyaluronic acid. Other areas of interventional dermatology have been well documented: myomodulation is an interesting concept that describes the impact of the injection depth of a filler on muscle forces in order to correct the balances between the lowering and elevators during congenital or acquired defcits with aging. Treatment of melasma remains diffcult but the prescription of oral tranexamic acid could be useful. Botulinum toxin is expanding its feld of activity for both aesthetic and medical treatments. Pulsed dye laser remains the reference treatment for port wine stains, but the rate of recurrence by post laser neo-angiogenesis justifes the need of reliable and effective adjuvant treatments.