Therapeutic Efficacy of Intralesional Steroid With Carbon Dioxide Laser Versus With Cryotherapy in Treatment of Keloids: A Randomized Controlled Trial

Artificial keloid skin models: understanding the pathophysiological mechanisms and application in therapeutic studies

Keloid is a type of scar formed by the overexpression of extracellular matrix substances from fibroblasts following inflammation after trauma. The existing keloid treatment methods include drug injection, surgical intervention, light exposure, cryotherapy, etc. However, these methods have limitations such as recurrence, low treatment efficacy, and side effects. Consequently, studies are being conducted on the treatment of keloids from the perspective of inflammatory mechanisms. In this study, keloid models are created to understand inflammatory mechanisms and explore treatment methods to address them. While previous studies have used animal models with gene mutations, chemical treatments, and keloid tissue transplantation, there are limitations in fully reproducing the characteristics of keloids unique to humans, and ethical issues related to animal welfare pose additional challenges. Consequently, studies are underway to create in vitro artificial skin models to simulate keloid disease and apply them to the development of treatments for skin diseases. In particular, herein, scaffold technologies that implement three-dimensional (3D) full-thickness keloid models are introduced to enhance mechanical properties as well as biological properties of tissues, such as cell proliferation, differentiation, and cellular interactions. It is anticipated that applying these technologies to the production of artificial skin for keloid simulation could contribute to the development of inflammatory keloid treatment techniques in the future.

Comparison of surgical excision followed by adjuvant radiotherapy and laser combined with steroids for the treatment of keloids: A systematic review and meta-analysis

This meta-analysis aims to evaluate and compare the effect of surgical excision followed by adjuvant radiotherapy and laser combined with steroids on keloids. Relevant studies reporting the recurrence rate or incidence of adverse events (AEs) were retrieved from the PubMed, Web of Science, Embase and Cochrane Library databases through August 2023. The quality of noncomparative single-arm clinical trials was evaluated using the methodological index for nonrandomised studies (MINORS) Methodological items. This meta-analysis was conducted utilizing Stata 12.0 statistical software. 26 studies involving 989 patients were included in the analysis. The recurrence rate in the laser combined with steroids therapy group (12.2%, 95% confidence interval [CI]: 5.9%-18.5%) was lower than that of the surgical excision combined with radiotherapy group (13.5%, 95% CI: 6.6%-22.2%). For the incidence of AEs, relatively low incidence of atrophy (0.0%, 95% CI: 0.0%-1.2%), telangiectasia (3.2%, 95% CI: 0.4%-7.6%), erythema (2.3%, 95% CI: 0.0%-10.6%), infection (0.2%, 95% CI: 0.0%-1.6%) and high hyperpigmentation rate (8.3%, 95% CI: 4.2%-13.4%) were obtained in the surgical excision combined with radiotherapy group. Compared with surgical resection followed by radiotherapy, the combination of laser and steroids for keloids showed a lower hyperpigmentation rate (6.5%), as well as a higher incidence of atrophy (22.7%), telangiectasia (6.4%), erythema (3.3%) and infection (3.3%). Only a hypopigmentation rate of 2.9% was obtained in patients treated with surgical excision plus radiotherapy. Current evidence revealed that surgical excision followed by adjuvant radiotherapy and laser combined with steroids therapy were effective and safe treatments for keloids, with relatively low recurrence rate and complication rate. Comparative studies are needed to further compare the effects of these two combination therapies on keloids.

Keloid treatments: an evidence-based systematic review of recent advances

BACKGROUND

Keloids are pathologic scars that pose a significant functional and cosmetic burden. They are challenging to treat, despite the multitude of treatment modalities currently available.

OBJECTIVE

The aim of this study was to conduct an evidence-based review of all prospective data regarding keloid treatments published between 2010 and 2020.

METHODS

A systematic literature search of PubMed (National Library of Medicine), Embase (Elsevier), and Cochrane Library (Wiley) was performed in November of 2020. Search strategies with the keywords "keloid" and "treatment" were performed by a medical librarian. The search was limited to prospective studies that were peer-reviewed, reported on clinical outcomes of keloid therapies, and were published in the English language between January 1, 2010, and November 24, 2020.

RESULTS

A total of 3462 unique citations were identified, of which 108 studies met inclusion criteria. Current literature supports silicone gel or sheeting with corticosteroid injections as first-line therapy for keloids. Adjuvant intralesional 5-fluorouracil (5-FU), bleomycin, or verapamil can be considered, although mixed results have been reported with each. Laser therapy can be used in combination with intralesional corticosteroids or topical steroids with occlusion to improve drug penetration. Excision of keloids with immediate post-excision radiation therapy is an effective option for recalcitrant lesions. Finally, silicone sheeting and pressure therapy have evidence for reducing keloid recurrence.

CONCLUSIONS

This review was limited by heterogeneity of subject characteristics and study outcome measures, small sample sizes, and inconsistent study designs. Larger and more robust controlled studies are necessary to further understand the variety of existing and emerging keloid treatments, including corticosteroids, cryotherapy, intralesional injections, lasers, photodynamic therapy, excision and radiation, pressure dressings, and others.

Laser therapy for treating hypertrophic and keloid scars

BACKGROUND

Hypertrophic and keloid scars are common skin conditions resulting from abnormal wound healing. They can cause itching, pain and have a negative physical and psychological impact on patients' lives. Different approaches are used aiming to improve these scars, including intralesional corticosteroids, surgery and more recently, laser therapy. Since laser therapy is expensive and may have adverse effects, it is critical to evaluate the potential benefits and harms of this therapy for treating hypertrophic and keloid scars.

OBJECTIVES

To assess the effects of laser therapy for treating hypertrophic and keloid scars.

SEARCH METHODS

In March 2021 we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL EBSCO Plus and LILACS. To identify additional studies, 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. There were no restrictions with respect to language, date of publication, or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) for treating hypertrophic or keloid scars (or both), comparing laser therapy with placebo, no intervention or another intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted the data, assessed the risk of bias of included studies and carried out GRADE assessments to assess the certainty of evidence. A third review author arbitrated if there were disagreements.

MAIN RESULTS

We included 15 RCTs, involving 604 participants (children and adults) with study sample sizes ranging from 10 to 120 participants (mean 40.27). Where studies randomised different parts of the same scar, each scar segment was the unit of analysis (906 scar segments). The length of participant follow-up varied from 12 weeks to 12 months. All included trials had a high risk of bias for at least one domain: all studies were deemed at high risk of bias due to lack of blinding of participants and personnel. The variability of intervention types, controls, follow-up periods and limitations with report data meant we pooled data for one comparison (and only two outcomes within this). Several review secondary outcomes - cosmesis, tolerance, preference for different modes of treatment, adherence, and change in quality of life - were not reported in any of the included studies. Laser versus no treatment: We found low-certainty evidence suggesting there may be more hypertrophic and keloid scar improvement (that is scars are less severe) in 585-nm pulsed-dye laser (PDL) -treated scars compared with no treatment (risk ratio (RR) 1.96; 95% confidence interval (CI): 1.11 to 3.45; two studies, 60 scar segments). It is unclear whether non-ablative fractional laser (NAFL) impacts on hypertrophic scar severity when compared with no treatment (very low-certainty evidence). It is unclear whether fractional carbon dioxide (CO2) laser impacts on hypertrophic and keloid scar severity compared with no treatment (very low-certainty evidence). Eight studies reported treatment-related adverse effects but did not provide enough data for further analyses. Laser versus other treatments: We are uncertain whether treatment with 585-nm PDL impacts on hypertrophic and keloid scar severity compared with intralesional corticosteroid triamcinolone acetonide (TAC), intralesional Fluorouracil (5-FU) or combined use of TAC plus 5-FU (very low-certainty evidence). It is also uncertain whether erbium laser impacts on hypertrophic scar severity when compared with TAC (very low-certainty evidence). Other comparisons included 585-nm PDL versus silicone gel sheeting, fractional CO2 laser versus TAC and fractional CO2 laser versus verapamil. However, the authors did not report enough data regarding the severity of scars to compare the interventions. As only very low-certainty evidence is available on treatment-related adverse effects, including pain, charring (skin burning so that the surface becomes blackened), telangiectasia (a condition in which tiny blood vessels cause thread-like red lines on the skin), skin atrophy (skin thinning), purpuric discolorations, hypopigmentation (skin colour becomes lighter), and erosion (loss of part of the top layer of skin, leaving a denuded surface) secondary to blistering, we are not able to draw conclusions as to how these treatments compare. Laser plus other treatment versus other treatment: It is unclear whether 585-nm PDL plus TAC plus 5-FU leads to a higher percentage of good to excellent improvement in hypertrophic and keloid scar severity compared with TAC plus 5-FU, as the certainty of evidence has been assessed as very low. Due to very low-certainty evidence, it is also uncertain whether CO2 laser plus TAC impacts on keloid scar severity compared with cryosurgery plus TAC. The evidence is also very uncertain about the effect of neodymium-doped yttrium aluminium garnet (Nd:YAG) laser plus intralesional corticosteroid diprospan plus 5-FU on scar severity compared with diprospan plus 5-FU and about the effect of helium-neon (He-Ne) laser plus decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream on scar severity compared with decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream. Only very low-certainty evidence is available on treatment-related adverse effects, including pain, atrophy, erythema, telangiectasia, hypopigmentation, regrowth, hyperpigmentation (skin colour becomes darker), and depigmentation (loss of colour from the skin). Therefore, we are not able to draw conclusions as to how these treatments compare.  AUTHORS' CONCLUSIONS: There is insufficient evidence to support or refute the effectiveness of laser therapy for treating hypertrophic and keloid scars. The available information is also insufficient to perform a more accurate analysis on treatment-related adverse effects related to laser therapy. Due to the heterogeneity of the studies, conflicting results, study design issues and small sample sizes, further high-quality trials, with validated scales and core outcome sets should be developed. These trials should take into consideration the consumers' opinion and values, the need for long-term follow-up and the necessity of reporting the rate of recurrence of scars to determine whether lasers may achieve superior results when compared with other therapies for treating hypertrophic and keloid scars.

A systematic review of randomised controlled trials investigating laser assisted drug delivery for the treatment of keloid and hypertrophic scars

The objective of this article is to study the clinical efficacy and adverse events of laser-assisted drug delivery in the treatment of hypertrophic and keloid scars. We searched the following databases up to 22 October 2020: the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (Clinical Trials) in The Cochrane Library, MEDLINE, EMBASE, and reference lists of articles for randomised clinical trials (RCTs) of laser-assisted drug delivery for the treatment of hypertrophic and keloid scars. We also searched online trials registries for ongoing trials and contacted trial authors where appropriate. Our outcomes of interest were objective clinical evaluation of scars, participant satisfaction, and adverse effects of the treatments. Two authors independently extracted data and assessed trial quality using Cochrane Risk of Bias 2. Two authors independently abstracted data. We included 10 RCTs involving a total of 329 participants: six trials utilised parallel-arm RCTs whilst four employed split-scar design. Three trials had high risk of bias with the remaining seven rated as having some concerns. The interventions and outcomes were too varied to be combined statistically. High-quality randomised controlled trials assessing laser-assisted delivery for drugs in the context of hypertrophic and/or keloid scarring are needed. Studies with a larger number of participants, with longer follow-up times, and standardised evaluation of outcome and adverse effects are warranted.

Effectiveness of a combination therapy using non-ablative fractional laser and intralesional triamcinolone injection for thyroidectomy scar treatment: a prospective, randomized, blinded pilot study

BACKGROUND

The occurrence of thyroid cancer has increased dramatically, and postoperative scars are placed at easily visible locations. Many patients show stronger desire for scar prevention. So far, numerous approaches have been discussed for the treatment of scars; this study is conducted to verify whether the early application of combined therapy contributes to minimal scar formation.

METHODS

Between March 2019 and December 2019, total of 64 patients with thyroidectomy scars of a size greater than 4.5 cm located on the anterior neck were enrolled in this prospective pilot study. Subjective and objective evaluation were carried out using the Patient and Observer Scar Assessment Scale (POSAS) at one, two, and six months after operation. Results were compared between a treatment group and a non-treatment group.

RESULTS

In PSAS score, the mean values of pain, itching sensation, pliability, thickness, and relief were significantly higher in the laser and steroid treatment group (p = 0.009, p = 0.000, p = 0.013, p = 0.002, and p = 0.007). The value of color of the scars showed no significant differences (p = 0.504). In OSAS score, parameter of thickness, relief, and surface area score was significantly higher score in the combination group (p = 0.029, 0.035, and 0.020), while vascularity, pigmentation, and pliability were not significantly different between two groups (p = 0.548, p = 0.983, and p = 0.128).

CONCLUSION

This study demonstrates that early combination therapy contributes to scar improvement to a meaningful extent based on POSAS. We believe that the combined therapy has a synergy effect on scar management, which improves the patients' quality of life in relation to their postoperative scars.

Efficacy and safety of laser combination therapy and laser alone therapy for keloid: a systematic review and meta-analysis

To evaluate the efficacy and safety of laser alone therapy and laser combination therapy (mainly combined with other kinds of laser or steroids) for keloid.PubMed, Embase and Web of Science were searched for relevant articles from inception to June 2020. Comprehensive Meta-Analysis software 2.0 (CMA) was used to perform the meta-analysis.A total of 29 articles were included in this meta-analysis. During the mean follow-up of 14 (1-84) months, the overall improvement rates of baseline Vancouver scar scale (VSS) score and itch were 0.454 (95%CI 0.351-0.561, I² = 0) and 0.786 (95%CI 0.613-0.895, I² = 0) in the laser combination therapy group. The improvement rates of scar height and flexibility in the laser combination therapy group were 0.629 (95%CI 0.519-0.727, I² = 52.089) and 0.784 (95%CI 0.251-0.975, I² = 89.420). The average improvement rate of the scar score in laser combination therapy was 0.338 (0.201-0.510); however, there were insufficient data for laser alone therapy comparison. The laser combination therapy had a greater pain improvement rate, 0.580 (0.389-0.750) versus 0.420 (0.224-0.645), compared to laser alone therapy, and a greater degree of good or excellent (> 50%) improvement in the overall scar, 0.636 (95%CI 0.347-0.852) versus 0.149 (95%CI 0.032-0.482), with laser alone therapy. Moreover, a lower regrowth rate of 0.187 (0.129-0.263) versus 0.249 (0.060-0.631), a lower post-treatment pigmentation rate of 0.125 (0.091-0.169) versus 0.135 (0.058-0.282), and a lower infection rate of 0.047 (0.009-0.209) versus 0.076 (0.012-0.351) were observed in the laser combination therapy compared with those rates in the laser alone therapy.The overall effect of laser combination therapy was better than that of laser alone therapy, and the incidence of adverse reactions was lower in laser combination therapy than in laser alone therapy.

Scientific landscape and trend analysis of keloid research: a 30-year bibliometric review

Background

Keloids remain troublesome for clinicians because of the lack of standard therapy, and the underlying mechanisms are still unclear. Bibliometric analysis could be a powerful tool to comprehensively review research trends, evaluate publication performances and provide future perspectives. There is no bibliometric analysis focusing on keloid research.

Methods

Keloid related publications were searched in Web of Science Core Collection from the publication year 1990 to 2019. Bibliometric data were provided on document type, annual publication number, most productive journals, publication geography, top potential authors, and highly cited articles. The distribution of single words in article titles was analyzed to evaluate the main research focuses and determine their development trends. Word cluster analysis was further performed to detect emerging trends in keloid research.

Results

The number of annual articles increased from 24 in 1990 to 63 in 2006 and then increased sharply, reaching 139 in 2019. Dermatologic Surgery published the highest number of articles followed by Plastic and Reconstructive Surgery. The USA ranked top with six publication indicators and China had a dramatic increase in the annual number of articles since 2012. Recent research hotspots include underlying pathogenetic mechanisms, keloid treatment, and therapeutic effect evaluation.

Discussion

Keloids remain a research focus. Efforts will be continuously made to understand the underlying mechanism of keloid formation. Despite many treatment modalities, there is no gold standard for keloid treatment, and many efforts are being made in the exploration of new therapies. Moreover, it is foreseeable that objective measurement tools will have a higher status in the assessment of keloids and scars.

Cryosurgery as a Single Agent and in Combination with Intralesional Corticosteroids Is Effective on Young, Small Keloids and Induces Characteristic Histological and Immunohistological Changes: A Prospective Randomized Trial

BACKGROUND

As the pathogenesis of keloids is poorly understood, there is no sound biological basis of keloid management. Few controlled therapeutic studies have been published, and recurrences are a major reason for treatment failure.

OBJECTIVE

To detect efficacy and safety of cryosurgery regimens on keloids and the occurring biological changes caused by the treatment.

METHODS

This prospective randomized study compared efficacy and tolerability as well as histological/immunohistochemical effects of liquid nitrogen contact cryosurgery as a single regimen (group A) and combined with intralesional corticosteroids (group B) on young (<2 years old), small (≤10 cm2) keloids in 40 patients (2-sided effect, α-error 1%, power 95%).

RESULTS

Marked flattening of the lesions was achieved by both regimens. Median lesional volumes decreased from 106 to 7 mm3 in group A (p = 0.001) and from 138 to 6 mm3 in group B (p < 0.0001; ns, between groups). Good to excellent responses were registered in 83.3 and 90% of patients in groups A and B, respectively, by evaluating the lesional volume, in 80 and 95% of patients by the physician's evaluation and in 95% of patients in either group by the patient's assessment. Follow-up of 6-36 months revealed no further significant changes. Cryosurgery was generally well tolerated, with minor pain during treatment not requiring (27.5%) or requiring local anaesthesia (5%) - but not analgesics -, and hypopigmentation (25%). Histological examination showed increased vessel number and lumen dilatation after treatment in group B and reduction of rete ridge length in both groups with more prominent changes in group A. Tenascin C staining demarcated keloids from normal skin before therapy, while after therapy the entire treated tissue was labelled. Interferon-γ expression was significantly decreased after therapy both regarding positively stained cells and intensity in both groups.

CONCLUSION

Cryosurgery without and with intralesional corticosteroids is effective and safe on young, small keloids not only as a destructive physical procedure, but also by inducing biochemical and immunological scar rejuvenation.

A Review of Current Keloid Management: Mainstay Monotherapies and Emerging Approaches

Commonly affecting those with skin of color, keloids are an aberrant wound response that leads to wound tissue expanding above and beyond the original cutaneous injury. Keloids are notoriously and particularly difficult to treat because of their tendency to recur after excision. The current standard of care is intralesional steroid (triamcinolone acetonide). However, because no therapy has yet proven to be fully curative, keloid treatments have expanded to include a number of options, from injections to multimodal approaches. This review details current treatment of keloids with injections (bleomycin, verapamil, hyaluronic acid and hyaluronidase, botulinum toxin, and collagenase), cryotherapy, laser, radiofrequency ablation, radiation, extracorporeal shockwave therapy, pentoxifylline, and dupilumab.

Surgical excision combined with fully ablative carbon dioxide laser therapy and triamcinolone injections as a potential treatment for keloids in children

BACKGROUND/OBJECTIVE

Keloids represent a functional and esthetic burden and can be particularly challenging to treat. Various topical, injectable, and ablative therapies exist but are associated with significant recurrence if used alone. We wanted to evaluate the long-term efficacy of multimodal therapy in pediatric patients treated for keloids at the Sainte-Justine University Hospital Center.

METHODS

We conducted a retrospective case study of 21 children with 21 keloids treated between April 2006 and April 2016. The following combination of treatments was studied: surgical excision, carbon dioxide (CO₂ ) laser therapy on the surgical site, and triamcinolone acetonide (TAC) intralesional injections during surgery and follow-up. Depending on the site treated, pressure garments and/or topical silicone were also used.

RESULTS

Of the 21 patients initially treated, four were lost to follow-up. Of the 17 patients who had adequate follow-up (mean duration 18 months, with periodic reassessments and additional TAC injections if needed), 6 (35%) had some recurrence, with remission in three of them following subsequent treatment and three lost to follow-up. In summary, 14 (82.4%) of the patients with adequate follow-up had complete clearance of the keloid. However, this must be interpreted in light of the fact there was a significant loss of follow-up (33.3%) from the initial cohort.

CONCLUSION

Our results are in agreement with other recent studies that demonstrate the need for multimodal therapy with combined methods in order to achieve long-term remission. A randomized controlled trial would be necessary to assess the real benefit of this treatment combination in children.

Combination therapy using non-ablative fractional laser and intralesional triamcinolone injection for hypertrophic scars and keloids treatment

Combinations of various treatment modalities were shown to be more effective than monotherapy when treating hypertrophic scars and keloids. This study was conducted to assess the effectiveness of combination therapy with non-ablative fractional laser and intralesional steroid injection. From May 2015 to June 2017, a total of 38 patients with hypertrophic scars or keloids were evaluated. The control group of 21 patients received steroid injection alone, and 17 patients (the combined group) received 1550-nm erbium-glass fractional laser treatment and steroid injection simultaneously. The mean number of treatment sessions was statistically fewer in the combined group than in the control group (6.95 vs 5.47, P = .042). There was a significant difference in the patient's scale in the combined group (14.62 vs 22.82, P = .005); however, the observer's scale was not significantly different (17.92 vs 20.55, P = .549). The recurrence rate was 38.1% (8/21) in the control group and 35.3% (6/17) in the combined groups and showed no significant difference (P = .859). However, the mean remission period was statistically longer in the combined group (3.00 months vs 4.17 months, P = .042). Combination therapy with non-ablative fractional laser and intralesional steroid injection showed better results for the treatment of hypertrophic scars and keloids with fewer treatment sessions, better patient satisfaction, and longer remission periods.

Pathophysiologic Mechanisms and Current Treatments for Cutaneous Sequelae of Burn Wounds

Burn injuries are a pervasive clinical problem. Extensive thermal trauma can be life-threatening or result in long-lasting complications, generating a significant impact on quality of life for patients as well as a cost burden to the healthcare system. The importance of addressing global or systemic issues such as resuscitation and management of inhalation injuries is not disputed but is beyond the scope of this review, which focuses on cutaneous pathophysiologic mechanisms for current treatments, both in the acute and long-term settings. Pathophysiological mechanisms of burn progression and wound healing are mediated by highly complex cascades of cellular and biochemical events, which become dysregulated in slow-healing wounds such as burns. Burns can result in fibroproliferative scarring, skin contractures, or chronic wounds that take weeks or months to heal. Burn injuries are highly individualized owing to wound-specific differences such as burn depth and surface area, in addition to patient-specific factors including genetics, immune competency, and age. Other extrinsic complications such as microbial infection can complicate wound healing, resulting in prolonged inflammation and delayed re-epithelialization. Although mortality is decreasing with advancements in burn care, morbidity from postburn deformities continues to be a challenge. Optimizing specialized acute care and late burn outcome intervention on a patient-by-patient basis is critical for successful management of burn wounds and the associated pathological scar outcome. Understanding the fundamentals of integument physiology and the cellular processes involved in wound healing is essential for designing effective treatment strategies for burn wound care as well as development of future therapies. Published 2018. Compr Physiol 8:371-405, 2018.