The use of botulinum toxin in keloid scar management: a literature review

Smart Use of Skin Biopsy Punch in Treating Keloids: A Single-Center Retrospective Study

BACKGROUND

Treatment of scarring has long been a problem due to high incidence and recurrence. Despite many existing treatment therapies, the efficacy remains unstable.

OBJECTIVES

To determine the efficacy and safety of skin biopsy punch in combination with corticosteroid injection (BPCI) in treating keloids.

APPROACH

This was a retrospective study. In total, 16 patients with keloids received BPCI. Changes in scar appearance, accompanied symptoms, and Vancouver Scar Scale (VSS) were analyzed. Patient satisfaction, VAS scores, and adverse effects were also evaluated.

RESULTS

Scar appearance, accompanied symptoms, and VSS scores improved significantly after the treatment. The total effective rate was 93.75% at an 18-month follow-up on average. The mean reduction rate of VSS score was 58.44% (p < 0.0001), especially in height and pliability (84.44% and 78.19%, p < 0.0001). The recurrence rate in this study was 12.5% (n = 2) at an 18-month follow-up on average. Mild adverse effects of pain, pruritus, hypopigmentation, and telangiectasia were recorded.

CONCLUSIONS

This study demonstrated BPCI might be an effective and safe therapy in keloids with a low long-time recurrence rate and well tolerance for patients.

LEVEL OF EVIDENCE IV

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Comprehensive Analysis of Current Treatment Approaches for Keloids in Pediatrics: A Systematic Review

Keloids, benign fibrous growths resulting from atypical skin responses to injuries, present a complex challenge in dermatology. These lesions, characterized by excessive collagen production, often lead to physical discomfort and psychological distress. While various treatment methods exist, the lack of a universally effective modality underscores the need for a systematic evaluation of current approaches. This systematic review aims to comprehensively analyze the current available treatment modalities used for the management of keloids in the pediatric population in terms of their effectiveness, safety, and quality of life outcomes. The review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search was conducted on PubMed and Google Scholar databases to identify relevant studies published in English. The review specifically focused on randomized controlled trials involving patients under 18 diagnosed with keloids, assessing different treatment modalities, and reporting validated measures of treatment efficacy, safety outcomes, and quality of life. The risk of bias was assessed using Cochrane's Risk of Bias Tool for randomized studies to ensure the methodological quality of the included trials. Four studies met the inclusion criteria, collectively involving 196 pediatric patients. Treatment interventions included glucocorticosteroid and fusidic acid cream with silicone gel patches, botulinum toxin type A injections, and Scarban silicone gel sheets. Patient-reported outcomes exhibited varying degrees of improvement in scar size, vascularity, and pliability. Complications, such as rash and wound infection, were reported in some cases. Based on our review of the selected studies and due to the incompletely understood pathogenesis of keloids, there is an ongoing lack of universally effective treatment modality for the management of keloids resulting in their persistently high recurrence rate.

Mechanotransduction in skin wound healing and scar formation: Potential therapeutic targets for controlling hypertrophic scarring

Hypertrophic scarring (HTS) is a major source of morbidity after cutaneous injury. Recent studies indicate that mechanical force significantly impacts wound healing and skin regeneration which opens up a new direction to combat scarring. Hence, a thorough understanding of the underlying mechanisms is essential in the development of efficacious scar therapeutics. This review provides an overview of the current understanding of the mechanotransduction signaling pathways in scar formation and some strategies that offload mechanical forces in the wounded region for scar prevention and treatment.

How Does Botulinum Toxin Inhibit Itch?

Two decades after reports of the anti-pruritic effects of botulinum neurotoxins (BoNTs), there is still no approved product for the anti-itch indication of BoNTs, and most clinical case reports still focus on the off-label use of BoNTs for various itchy conditions. Few randomized clinical trials have been conducted with controversial results, and the beneficial effects of BoNTs against itch are mainly based on case studies and case series. These studies are valuable in presenting the potential application of BoNTs in chronic pruritic conditions, but due to the nature of these studies, they are categorized as providing lower levels of evidence or lower grades of recommendation. To obtain approval for the anti-pruritic indication of BoNTs, higher levels of evidence are required, which can be achieved through conducting large-scale and well-designed studies with proper control groups and established careful and reliable primary and secondary outcomes. In addition to clinical evidence, presenting the mechanism-based antipruritic action of BoNTs can potentially strengthen, accelerate, and facilitate the current efforts towards further investments in accelerating the field towards the potential approval of BoNTs for itchy conditions. This review, therefore, aimed to provide the state-of-the-art mechanisms underlying the anti-itch effect of BoNTs from basic studies that resemble various clinical conditions with itch as a hallmark. Evidence of the neuronal, glial, and immune modulatory actions of BoNTs in reducing the transmission of itch are presented, and future potential directions are outlined.

Toxicology and pharmacology of botulinum and tetanus neurotoxins: an update

Tetanus and botulinum neurotoxins cause the neuroparalytic syndromes of tetanus and botulism, respectively, by delivering inside different types of neurons, metalloproteases specifically cleaving the SNARE proteins that are essential for the release of neurotransmitters. Research on their mechanism of action is intensively carried out in order to devise improved therapies based on antibodies and chemical drugs. Recently, major results have been obtained with human monoclonal antibodies and with single chain antibodies that have allowed one to neutralize the metalloprotease activity of botulinum neurotoxin type A1 inside neurons. In addition, a method has been devised to induce a rapid molecular evolution of the metalloprotease domain of botulinum neurotoxin followed by selection driven to re-target the metalloprotease activity versus novel targets with respect to the SNARE proteins. At the same time, an intense and wide spectrum clinical research on novel therapeutics based on botulinum neurotoxins is carried out, which are also reviewed here.

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.

Utilities of Botulinum Toxins in Dermatology and Cosmetology

Botulinum toxin (BoNT) is a neurotoxin produced by the Clostridium botulinum bacterium with a well-known efficacy and safety profile in the focal idiopathic hyperhidrosis treatment. BoNT comprises seven different neurotoxins; however, only toxins A and B are clinically employed. BoNT is lately practiced in off-label therapies for a variety of skin diseases. Scar prevention, hyperhidrosis, rhytides, eccrine nevus, alopecia, psoriasis, Darier disease, bullous skin disease, pompholyx and Raynaud's phenomenon are some of the novel indications for BoNT in cosmetic and notably non-cosmetic aspects of dermatology. To employ BoNT correctly in clinical practice, we must have a thorough understanding of the functional anatomy of the mimetic muscles. An intensive literature search was conducted to update all dermatology-oriented experiments and clinical trials on the described element of BoNT for this general overview of BoNT use in dermatology. This review aims to analyse the role of BoNT in dermatology and cosmetology.

Novel targets and therapies for keloid

Keloids are the result of aberrant tissue scarring typically occurring in injured skin, and are caused by the overgrowth of granulation tissue or collagen type III during the healing process. There is a genetic component, thus a predisposition can be genetically transmitted. Keloids are difficult to treat because of their postexcisional recurrence, and they have an impact on patient quality of life due to psychological distress caused by cosmetic concerns and functional disability. Treatment ranges from classic corticosteroid therapy to multimodal approaches such as injections, cryotherapy, laser, radiation, radiofrequency ablation and extracorporeal shockwave therapy. Recent discoveries into the pathogenesis of keloid have enabled clinicians to expand the therapeutic options for treatment. The aim of this paper was to review the literature, clarify the general concept of keloid development, and assess emerging treatment options such as stem cell therapy, mitomycin C, bleomycin, interferon, botulinum toxin type A, calcium channel blockers, angiotensin-converting enzyme inhibitors and fat grafting, and the evolutionary advancement towards epigenetic modifications and gene therapy.

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.