Current Research of Botulinum Toxin Type A in Prevention and Treatment on Pathological Scars

The Efficacy of Botulinum Toxin Type A (BTA) in the Treatment of Hypertrophic Scars and Keloids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Hypertrophic scars cause significant physical and emotional discomfort. Botulinum toxin type A (BTA) has shown promising outcomes in reducing scar formation. Research suggested its effectiveness in managing hypertrophic scars and keloids. This systematic review and meta-analysis were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, including randomized controlled trials (RCTs). The included studies involved patients with hypertrophic scars treated with BTA. Five databases were searched from inception to August 2024. Studies were screened and selected by two independent reviewers. Data on study design, patient demographics, and interventions was extracted. The risk of bias (ROB) was assessed using the ROB revised tool developed by Cochrane (ROB2). Meta-analysis was performed using RevMan Web (The Cochrane Collaboration, London, UK) with a random-effects model due to high heterogeneity, calculating mean differences for the primary and secondary outcomes. Outcomes included Vancouver Scar Scale (VSS) scores, scar thickness, vascularity, pliability, and pigmentation. The systematic review identified 182 records from five databases. The screening process resulted in seven studies included in the final analysis after assessment for eligibility. The efficacy of BTA in treating hypertrophic scars and keloids was assessed. The meta-analysis showed that BTA significantly improved VSS scores, with a pooled mean difference of -1.69 (P = 0.01). However, BTA did not show a statistically significant effect on reducing scar height/thickness or improving vascularity. Scar pliability was significantly improved by BTA, with a pooled mean difference of -0.76 (P = 0.002), while there was no significant effect on pigmentation. High heterogeneity was observed across the studies. BTA could be used as an effective treatment for the components of hypertrophic scars and keloids, especially regarding their pliability and improving scar quality. However, for functions such as the change in scar height, vascularity, and pigmentation, more research is still required among larger RCTs. Future research should focus on refining the treatment regimens and the mode of action of BTA to the scar tissue.

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.

Dose-Dependent Effects of Botulinum Toxin Type A on Prevention of Postoperative Scars in Various Regions in the Body: A Prospective, Double-Blind Randomized Controlled Trial

BACKGROUND

Botulinum toxin type A (BTXA) can improve wound healing and reduce scar formation; however, the exact dose required to prevent postoperative scarring across various anatomical sites remains unclear. This study aimed to investigate the effectiveness and optimal concentrations of BTXA for preventing postoperative scarring across various common surgical sites throughout the body.

METHODS

In this prospective randomized controlled trial, 46 patients with benign skin tumors received injections of 1, 2.5, or 5 U/0.1 mL of BTXA or 0.9% saline immediately following surgical tumor excision on both sides of the incisions. Follow-ups were conducted at 7 days, 15 days, and 1, 3, and 6 months postoperatively. Patient-reported adverse events and standardized digital photographs were collected. Scar formation was assessed using the modified Stony Brook Scar Evaluation Scale (mSBSES).

RESULTS

All 46 patients completed the trial without severe complications. The mSBSES scores were higher in the experimental groups at all follow-ups. The 5 U/0.1 mL BTXA dose group demonstrated optimal scar prevention at all high-risk sites for scar hyperplasia. No significant difference was observed between the 2.5 U/0.1 mL and 5 U/0.1 mL doses for intermediate-risk sites, while 1 U/0.1 mL dose was sufficient for low-risk sites. Overall, 86.5% of patients were satisfied with their treatments, with 16.3% being very satisfied.

CONCLUSIONS

Early postoperative BTXA injection can reduce or prevent hypertrophic scarring, with optimal doses ranging from 1 to 5 U/0.1 mL depending on the surgical site, supporting broader clinical application of BTXA. The effectiveness of different concentrations of botulinum toxin type A (BTXA) in preventing postoperative scarring was compared, expanding the scope of previous research, which focused only on the head, face, and neck regions, to include the trunk and extremity areas. Different optimal injection strategies were determined based on different surgical sites and their risks of developing hypertrophic scars. The study demonstrates that BTXA not only reduces scar formation but also enhances patient satisfaction and reduces postoperative itching and pain, contributing to overall better postoperative outcomes. By establishing the efficacy and optimal dosing of BTXA for various surgical sites, this research supports the potential for broader clinical application of BTXA in aesthetic and reconstructive surgeries.

LEVEL OF EVIDENCE I

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 .

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.

Trapdoor Deformity Correction Post Nasal Bilobed Flaps for Basal Cell Carcinoma Reconstruction With Multiple Laser Modalities

ABSTRACT

In case of excision of nasal basal cell carcinoma (BCC), bilobed flaps are considered the criterion standard of reconstruction for defect less than 15 mm in size. However, there is still a risk of trapdoor deformity formation, of which its treatment is less discussed. A 44-year-old woman who was diagnosed with nasal BCC and underwent tumor excision with bilobed flap reconstruction presented with trapdoor deformity postoperatively. The computed Vancouver Scar Scale was 7. After early intervention of multiple laser modalities, including 2 sessions of 585-nm pulsed dye laser with a fluence of 9 J/cm2, pulse duration of 6 milliseconds, and spot size of 6 mm, 2940-nm Er-yttrium aluminum garnet (YAG) laser with a pulse energy of 800-900 mJ, repetition rate of 8-9 Hz, and laser spot size of 3-7 mm, and 5 sessions of 1064-nm Nd:YAG fractional picosecond laser with a pulse energy of 2.30-2.70 mJ, repetition rate of 8 Hz, and laser spot size of 6 mm from 5 to 23 weeks postoperatively, the Vancouver Scar Scale score improved to 1, with significant reduction of trapdoor scar erythema and puffiness. Although BCC is often curable, tumor excision causes unsatisfactory appearance satisfaction problem, owing to the apparent location of the lesion. Factors, such as sebaceous tissue thickness, reconstruction over multiple aesthetic subunits of nose, and damage to nasal cartilage framework structure during tumor removal, may increase the risk of trapdoor formation. Early intervention with multiple laser treatment can significantly revise the deformity.

Botulinum Toxin-A for the Treatment of Neuropathic Pain after Decompressive Craniotomy in Stroke: Two Cases

Botulinum toxin-A (BoNT-A) is recommended as third-line off-label treatment for the management of neuropathic pain. BoNT-A has been reported as treatment for different neuropathic pain conditions; however, not for neuropathic pain after decompressive craniotomy for stroke. The aim of this retrospective case series is to provide information on safety, the effect, and the application method of BoNT-A in clinical practice for the treatment of neuropathic pain after trepanation. This case series describes 2 patients treated in 2021 at a BoNT outpatient clinic for chronic neuropathic pain at the incisional site after decompressive craniotomy for stroke who were resistant to pain medication. Cases were a 48-year-old woman and a 63-year-old man suffering from chronic neuropathic pain since 3 and 6 years, respectively. They were treated regularly with BoNT-A with a total dose of 100 mouse units of incobotulinumtoxin-A injected into peri-incisional sites of the scalp. Both patients reported subjective decrease in pain frequency (40% and 60%), in pain intensity (60% and 90%), and an increase of quality of life (80%). BoNT-A should be further investigated as treatment for neuropathic pain - especially in underreported conditions such as neuropathic pain after craniotomy in stroke.