Keloids and hypertrophic scars: review and treatment strategies

Keloids: prevention and management

Keloids result from an abnormal wound-healing process in which the normal regulatory pathways during tissue regeneration and scar remodeling are disrupted. While the pathogenesis of keloids continues to be investigated, numerous treatment options exist. Although prevention of keloid formation is the best management, early recognition of keloid formation is integral in treatment and prevention of recurrence. Surgical resection with adjuvant silicone gel sheeting or triamcinolone injection is common, but can still result in recurrence. New treatments include chemotherapeutics such as 5-fluorouracil, bleomycin, and mitomycin C. Although further clinical investigation is required for newer treatments, initial results are promising.

Involvement of upper torso stress amplification, tissue compression and distortion in the pathogenesis of keloids

Keloids are benign tumours composed of fibrous tissue produced during excessive tissue repair triggered by minor injury, trauma or surgical incision. Although it is recognized that keloids have a propensity to form in the upper torso of the body, the predisposing factors responsible for this have not been investigated. It is crucial that the aetiopathoical factors implicated in keloid formation be established to provide guidelines for well-informed more successful treatment. We compared keloid-prone and keloid-protected skin, identified pertinent morphological differences and explored how inherent structural characteristics and intrinsic factors may promote keloid formation. It was determined that keloid prone areas were covered with high tension skin that had low stretch and a low elastic modulus when compared with skin in keloid protected areas where the skin was lax with a high elastic modulus and low pre-stress level. Factors contributing to elevated internal stress in keloid susceptible skin were the protrusion of hard connective tissue such as bony prominences or cartilage into the dermis of skin as well as inherent skin characteristics such as the bundled arrangement of collagen in the reticular dermis, the existent high tension, the low elastic modulus, low stretch ability, contractile forces exerted by wound healing fibroblastic cells and external forces. Stress promotes keloid formation by causing dermal distortion and compression which subsequently stimulate proliferation and enhanced protein synthesis in wound healing fibroblastic cells. The strain caused by stress also compresses and occludes microvessels causing ischaemic effects and reperfusion injury which stimulate growth when blood rich in growth factors returns to the tissue. The growth promoting effects of increased internal stress, primarily, and growth factors released by reperfusing blood, manifest in keloid formation. Other inherent skin characteristics promoting keloid growth during the late stages of wound healing in the upper torso are the thinner epidermis, the presence of vellus hairs, the absence of protective immunoglobulin A (IgA), and the thick fragile quality of upper torso skin. As it is not known why there is a predilection for keloids to form in the upper torso of the body, this hypothesis implicating and associating inherent morphological characteristics and elevated stress in the aetiopathogenesis of keloids is of potential value in terms of prevention, management and treatment of these enigmatic tumours.

Automated classification of healthy and keloidal collagen patterns based on processing of SHG images of human skin

All-optical microspectroscopic and tomographic tools have a great potential for the clinical investigation of human skin and skin diseases. However, automated optical tomography or even microscopy generate immense data sets. Therefore, in order to implement such diagnostic tools into the medical practice in both hospitals and private practice, there is a need for automated data handling and image analysis ideally implementing automized scores to judge the physiological state of a tissue section. In this contribution, the potential of an image processing algorithm for the automated classification of skin into normal or keloid based on second-harmonic generation (SHG) microscopic images is demonstrated. Such SHG data is routinely recorded within a multimodal imaging approach. The classification of the tissue implemented in the algorithm employs the geometrical features of collagen patterns that differ depending on the constitution, i.e., physiological status of the skin.

Insights gained from the reverse engineering of gene networks in keloid fibroblasts

Background

Keloids are protrusive claw-like scars that have a propensity to recur even after surgery, and its molecular etiology remains elusive. The goal of reverse engineering is to infer gene networks from observational data, thus providing insight into the inner workings of a cell. However, most attempts at modeling biological networks have been done using simulated data. This study aims to highlight some of the issues involved in working with experimental data, and at the same time gain some insights into the transcriptional regulatory mechanism present in keloid fibroblasts.

Methods

Microarray data from our previous study was combined with microarray data obtained from the literature as well as new microarray data generated by our group. For the physical approach, we used the fREDUCE algorithm for correlating expression values to binding motifs. For the influence approach, we compared the Bayesian algorithm BANJO with the information theoretic method ARACNE in terms of performance in recovering known influence networks obtained from the KEGG database. In addition, we also compared the performance of different normalization methods as well as different types of gene networks.

Results

Using the physical approach, we found consensus sequences that were active in the keloid condition, as well as some sequences that were responsive to steroids, a commonly used treatment for keloids. From the influence approach, we found that BANJO was better at recovering the gene networks compared to ARACNE and that transcriptional networks were better suited for network recovery compared to cytokine-receptor interaction networks and intracellular signaling networks. We also found that the NFKB transcriptional network that was inferred from normal fibroblast data was more accurate compared to that inferred from keloid data, suggesting a more robust network in the keloid condition.

Conclusions

Consensus sequences that were found from this study are possible transcription factor binding sites and could be explored for developing future keloid treatments or for improving the efficacy of current steroid treatments. We also found that the combination of the Bayesian algorithm, RMA normalization and transcriptional networks gave the best reconstruction results and this could serve as a guide for future influence approaches dealing with experimental data.

Efficacy and safety of 1064-nm Q-switched Nd:YAG laser with low fluence for keloids and hypertrophic scars

BACKGROUND

Several treatment modalities using laser devices have been used for the treatment of keloids and hypertrophic scars with various therapeutic outcomes.

OBJECTIVE

The purpose of this study was to describe the efficacy and safety of 1064-nm Q-switched (QS) Nd:YAG laser with low fluence on keloids and hypertrophic scars.

METHODS

Keloids and hypertrophic scars located at 21 anatomic sites in 12 Korean patients (10 men and 2 women; mean age 23.8 years, range 21-33) were treated using 1064-nm QS Nd:YAG laser with low fluence at 1-2 week intervals. Treatment settings were 1.8-2.2 J/cm(2), 7-mm spot size and 5-6 passes with appropriate overlapping.

RESULTS

Follow-up data collected 3 months after the final treatment revealed decreases in the mean score for the following lesion characteristics: pigmentation from 1.8 to 1.2; vascularity from 1.4 to 1.0; pliability from 3.0 to 2.0 and height from 2.3 to 1.8. The modified Vancouver General Hospital Burn Scar Assessment score decreased from 8.6 to 5.9 (P < 0.0001). Observed side-effects were a mild prickling sensation during treatment, and mild post-treatment erythema, both of which resolved within few hours.

CONCLUSION

Our results demonstrate that QS Nd:YAG laser with low fluence may be used for the treatment of keloids and hypertrophic scars.

A review of the effectiveness of antimitotic drug injections for hypertrophic scars and keloids

Hypertrophic scars and keloids are common problems after injury and cause functional and cosmetic deformities. A wide variety of treatments have been advocated for hypertrophic scars and keloids regression. Unfortunately, the reported efficacy has been variable. This article explores antimitotic drugs described in the literature such as steroid injection, 5-FU, mitomycin C, and bleomycin, which mainly target the fibroblasts in scar tissue, have been proposed as the effective modalities for scar treatment and scar prevention after surgery, but restricted due to possible side effects. The current accepted treatment for hypertrophic scar and keloid are combination therapy and the early treatment which could achieve better efficacy and less adverse effect.

Effects of antisense oligodeoxynucleotide to type I collagen gene on hypertrophic scars in the transplanted nude mouse model

BACKGROUND

Antisense nucleic acids are effective in inhibiting harmful or uncontrolled gene expression. We had previously proved that the antisense DNA to type I collagen could effectively inhibit the synthesis of collagen type I in cultured hypertrophic scar fibroblasts, suggesting a potential role in anti-scarring, but there are no published reports of its effect on scar in the transplanted nude mouse model.

AIMS

To investigate the effects of antisense oligodeoxynucleotide (ASODN) to type I collagen gene on hypertrophic scars in the transplanted nude mouse model and clarify the potential of ASODN for the treatment of scars.

METHODS

The nudemousemodel of hypertrophic scar was created and subjected to daily injections with ASODN and LipofectamineTM for 2 ,4 or 6 weeks.We then examined the scars for changes in histopathological characteristics. The effects of ASODNon type I collagen gene expression were examined by reverse transcription-polymerase chain reaction and Western blots.

RESULTS

The ASODN could remarkably alleviate the scar in the nude mouse model and consistently inhibit type I collagen gene expression at both the mRNA and protein levels.

CONCLUSION

ASODN was effective in downregulating type I collagen gene expression and could prove to be useful in the treatment of scars.

Keloidoscope: in search for the ideal treatment of keloids

Although keloids were recognised in the Smith Papyrus of ancient times, the precise definition, cause and management have remained elusive. Several forms of treatment have been used with varying success.Objectives This study assesses and compares the value of intralesional steroid (Triamcinolone acetonide 40mg/ml), cryotherapy and cryotherapy with intralesional steroid in the treatment of keloids.Methodology 33 patients were studied, 11 each in the three arms and the volume of the keloids was recorded using wax patterns of alginate impressions of the keloids to note the change in size postoperatively.Results The best average percentage response was observed is patients who received both Cryotherapy (CRY) and Intralesional Steroid (ILS) (69.02%) followed by patients who received only intralesional steroid (43.98%). Among the patients who received only cryotherapy, the average percentage response was only 39.24%. 72.73% patients who received intralesional steroid with cryotherapy showed more than 50% improvement (good response) while only 9.09% patients who received intralesional steroid alone and cryotherapy alone showed similar improvement.Conclusion In patients with keloids good response can be obtained with CRY with ILS as compared to ILS alone and CRY alone.

About strawberry, crab claws, and the Sir James Black's invention. Hypothesis: can we battle keloids with propranolol?

The cutaneous hemangiomas of infancy or infantile hemangiomas are the most common benign tumor of childhood. They were formerly known as strawberry hemangiomas in reason of its typical appearance although uncommon morphologic variations can be found. Usually hemangiomas are harmless growths that are the result of proliferation of endothelial cells during early childhood. Involution of the lesion occurs at 12-18 months and can last up to 7 years. Occasionally, infantile hemangiomas suffer dramatic overgrowth causing esthetical damages, as well compromises to vital structures that requires prompt intervention. Propranolol, a beta-adrenergic receptor antagonist that was invented by Sir James Black in 1960s, appears to be an effective treatment for infantile hemangiomas and should now be used as a first-line treatment in hemangiomas when intervention is required. Keloids (that resembles crab claws) and hypertrophic scars are fibrous tissue outgrowths that result from a derailment in the normal wound-healing process. Systemic or intralesional propranolol may play a role in the amelioration of keloids and hypertrophic scars due to their potential to induce vasoconstriction of over proliferating tissues, triggering apoptosis of endothelial cells and also to their effect as modulator of inflammatory process during wound healing. In adding the propranolol to the melting pot of abnormal (or supra-normal) wound healing, we hypothesized that we can battle keloids with propranolol.

Attenuation of alpha1 collagen production with antisense ribonucleic acid in cultured hypertrophic scar fibroblasts

BACKGROUND

It has been demonstrated that hypertrophic scar fibroblasts (HSFs) overexpress collagen messenger ribonucleic acid (mRNA) and protein, especially alpha1 collagen. Antisense nucleic acids are effective in inhibiting harmful or uncontrolled gene expression, suggesting that antisense ribonucleic acid (RNA) can effectively downregulate the expression of alpha1 collagen gene and attenuate the scars.

AIMS

This study was conducted to observe the effect of recombinant plasmid pREP9-COL1 on alpha1 collagen expression in HSFs and clarify the prospect of antisense RNA on scar treatment.

METHODS

The alpha1 collagen gene fragment including the region of 5' UTR to exon (229 bp) was cloned in the eukaryotic expression plasmid pREP9 in the antisense orientation relative to the RSV-LTR promoter to reconstruct the pREP9- COL1 plasmid. Then it was transferred into HSFs through lipofectamine. The expression of alpha1 collagen was examined by immunostaining, reverse-transcriptase polymerase chain reaction, and Western blots.

RESULTS

The recombinant plasmid pREP9-COL1 with a correct sequence was constructed successfully; pREP9-COL1 consistently inhibited human alpha1 collagen gene expression at both mRNA and protein levels.

CONCLUSIONS

Antisense RNA was effective in downregulating alpha1 collagen expression of HSFs. Therefore, this approach offered a prospect of scar treatment by attenuation of alpha1 collagen production with antisense RNA.

Hepatoma-derived growth factor and its role in keloid pathogenesis

Hepatoma-derived growth factor (HDGF) is a novel mitogenic growth factor that has been implicated in many different carcinomas. Its role in keloid biology has not yet been investigated. The present study is aimed at examining the role of HDGF in keloid pathogenesis. Immunohistochemical staining and Western blot analyses were used to examine in vivo localization and expression of HDGF in keloid and normal skin tissue. This was followed by the detection of HDGF expression in fibroblasts cultured in vitro and fibroblasts exposed to serum. To investigate the effect of epithelial–mesenchymal interactions, a two-chamber system was employed in which keratinocytes on membrane inserts were co-cultured with the fibroblasts. HDGF expression levels in all cell extracts and conditioned media were assayed through Western blot analysis. In another set of experiments, the effect of exogenous recombinant HDGF on keloid fibroblasts (KF) and normal fibroblasts (NF) was examined. Cell proliferation was assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and by quantifying proliferating cell nuclear antigen (PCNA) expression. Downstream targets of HDGF were identified by detecting their expression through Western blot analysis. Our results indicate that there was an increase in HDGF expression in the dermis of keloid compared with normal skin tissue. The application of serum and epithelial–mesenchymal interactions did not seem to have any effect on intracellular HDGF expression levels. However, co-culturing keloid keratinocytes with KFs resulted in increased HDGF secretion when compared with monoculture or normal controls. Furthermore, treatment with exogenous recombinant HDGF was found to increase the proliferation of KFs, activate the extracellular signal-regulated kinase (ERK) pathway and up-regulate the secretion of vascular endothelial growth factor (VEGF).

Hypertrophic scars and keloids--a review of their pathophysiology, risk factors, and therapeutic management

BACKGROUND

Hypertrophic scars and keloids result from an abnormal fibrous wound healing process in which tissue repair and regeneration-regulating mechanism control is lost. These abnormal fibrous growths present a major therapeutic dilemma and challenge to the plastic surgeon because they are disfiguring and frequently recur.

OBJECTIVE

To provide updated clinical and experimental information on hypertrophic scars and keloids so that physicians can better understand and properly treat such lesions.

METHODS

A Medline literature search was performed for relevant publications and for diverse strategies for management of hypertrophic scars and keloids.

CONCLUSION

The growing understanding of the molecular processes of normal and abnormal wound healing is promising for discovery of novel approaches for the management of hypertrophic scars and keloids. Although optimal treatment of these lesions remains undefined, successful healing can be achieved only with combined multidisciplinary therapeutic regimens.

Antimitotic drug injections and radiotherapy: a review of the effectiveness of treatment for hypertrophic scars and keloids

Scars are a common complication of surgery or burn wound management. Scars occur over the body, affecting people of both sexes and all ages. Scar therapy is a constant clinical challenge; antimitotic drugs and radiotherapy are used with varying degrees of success. This article examines the success of both these types of treatment modalities.

Effects of basic fibroblast growth factors on hypertrophic scarring in a rabbit ear model

BACKGROUND

Basic fibroblast growth factor (bFGF) was clinically proven to accelerate acute and chronic wound healing. Accelerated wound healing may lead to improved scarring. These studies suggested a possible antiscarring effect of bFGF during wound healing. Little was known about the precise pathologic mechanisms of bFGF on scarring formation.

AIMS

The aim of this study was to investigate the effect of bFGF on hypertrophic scarring in a rabbit ear model and clarify the mechanism of bFGF on scar treatment.

METHODS

The rabbit model of hypertrophic scarring was created and received of a low- or high-dose topical treatment three times daily for 1, 2, or 3 months. Then we examined the changes in the macroscopic and histopathologic characteristics of the scars. The expression of collagen, alpha(1)beta(2) integrin, and matrix metalloproteinase 1 (MMP-1) was studied by applying reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blotting.

RESULT

High-dose bFGF remarkably alleviated the scar in the rabbit ear model and decreased collagen type I expression. Further study revealed that bFGF remarkably enhanced MMP-1 and decreased alpha(1)beta(2) integrin expression.

CONCLUSION

This study supports the hypothesis that bFGF exerted a net negative effect on collagen remodeling, therefore suggesting a potential antiscarring role.

Prevention and management of hypertrophic scars and keloids after burns in children

Hypertrophic scars and keloids are challenging to manage, particularly as sequelae of burns in children in whom the psychologic burden and skin characteristics differ substantially from adults. Prevention of hypertrophic scars and keloids after burns is currently the best strategy in their management to avoid permanent functional and aesthetical alterations. Several actions can be taken to prevent their occurrence, including parental and children education regarding handling sources of fire and flammable materials, among others. Combination of therapies is the mainstay of current burn scar management, including surgical reconstruction, pressure therapy, silicon gels and sheets, and temporary garments. Other adjuvant therapies such as topical imiquimod, tacrolimus, and retinoids, as well as intralesional corticosteroids, 5-fluorouracil, interferons, and bleomycin, have been used with relative success. Cryosurgery and lasers have also been reported as alternatives. Newer treatments aimed at molecular targets such as cytokines, growth factors, and gene therapy, currently in developing stages, are considered the future of the treatment of postburn hypertrophic scars and keloids in children.

Collagen synthesis is suppressed in dermal fibroblasts by the human antimicrobial peptide LL-37

LL-37 is a human cathelicidin antimicrobial peptide that is released in the skin after injury and acts to defend against infection and modulate the local cellular immune response. We observed in human dermal keloids that fibrosis was inversely related to the expression of cathelicidin and sought to determine how LL-37 influenced expression of types I and III collagen genes in dermal fibroblasts. At nano-molar concentrations, LL-37 inhibited baseline and transforming growth factor-beta-induced collagen expression. At these concentrations, LL-37 also induced phosphorylation of extracellular signal-regulated kinase (ERK) within 30 minutes. Activation of ERK, and the activation of a G-protein-dependent pathway, was essential for inhibition of collagen expression as pertussis toxin or an inhibitor of ERK blocked the inhibitory effects of LL-37. c-Jun N-terminal kinase and p38 mitogen-activated protein kinase inhibitors did not alter the effects of cathelicidin. Silencing of the Ets-1 reversed inhibitory effects of LL-37. Taken together, these findings show that LL-37 can directly act on dermal fibroblasts and may have antifibrotic action during the wound repair process.

Laser in the treatment of hypertrophic burn scars

This prospective study looked at the outcome of laser (light amplification by stimulated emission of radiation) treatment for hypertrophic scarring. Dermatrade mark K laser (a set of combined lasers erbium:yttrium aluminium garnet/carbon dioxide, qualified as a class IV laser) was used. Between 21 June 2000 and 19 November 2002, at the Siemianowice Burn Center, Poland, 592 interventions, using laser, were performed on N= 327 patients (220 women and 107 men, aged between 3 and 80 years). The majority of cases [N= 223 (68.9%)] were patients with post-burn hypertrophic scars, and 104 cases (31.8%) had various types of hypertrophic scars. Evaluation took place using an adapted Vancouver Scar Scale and digital photographs as well as the patient's opinion. It was noted that after laser treatment, satisfactory results were achieved in 72% of cases. The scars had become less red (192/327 scored no redness at the end of the study versus 92/327 upon initial), less raised (272/327 scored a flat scar versus 72/327 upon initial) and demonstrated an improved viscoelasticity (192/327 scored a soft skin versus 62/327 upon initial). Laser treatment did not improve contractures in post-burn hypertrophic scars. Results were not confirmed using objective measurement tools, as these were not available to us.

[A comparative clinical study of the treatment of hypertrophic scars with either intralaesional steroid or silicone gel sheeting]

The linear (or "surgical") hypertrophic scar is the most common type of pathologic scarring. There has been a steady increase in the number of patients with hypertrophic scars over the years due to the rising number of operative interventions altogether. However, the therapeutic protocols are not homogeneous and they show significant variations. 200 cases with hypertrophic scars were treated by the authors from April 2001 to March 2004. 24 patients were selected in the study from these cases; and two randomized groups were formed. Each group included 12-12 patients, who were treated with either intralaesional steroid or silicone gel sheeting. The therapeutic protocols were defined by the authors. The aim of this study was to compare and determine the roles of these two commonly used treatment options of hypertrophic scars. The authors present patient demographics; and analyze the results and outcome of the study. Both methods were efficient significantly, however intralaesional steroid therapy had a more rapid effect and it lasted longer than silicone gel sheeting. These results confirmed the role of these two treatment modalities in the protocols. The authors concluded that silicone gel sheeting is the first line, while intralaesional steroid is the second line treatment for primary linear hypertrophic scars. Based on the authors' experience, in recurrent linear hypertrophic scars, intralaesional steroid therapy is recommended in first line, because silicone gel sheeting was largely ineffective. Prospective randomized clinical trials should be needed to further clarify their role in the treatment protocols.

A review of the biologic effects, clinical efficacy, and safety of silicone elastomer sheeting for hypertrophic and keloid scar treatment and management

Silicone elastomer sheeting is a medical device used to prevent the development of and improve the appearance and feel of hypertrophic and keloid scars. The precise mechanism of action of silicone elastomer sheeting has not been defined, but clinical trials report that this device is safe and effective for the treatment and prevention of hypertrophic and keloid scars if worn over the scar for 12 to 24 hours per day for at least 2 to 3 months. Some of the silicone elastomer sheeting products currently on the market are durable and adhere well to the skin. These products are an attractive treatment option because of their ease of use and low risk of adverse effects compared to other treatments, such as surgical excision, intralesional corticosteroid injections, pressure therapy, radiation, laser treatment, and cryotherapy. Additional controlled clinical trials with large patient populations may provide further evidence for the efficacy of silicone elastomer sheeting in the treatment and prevention of hypertrophic and keloid scars. The purpose of this article is to review the literature on silicone elastomer sheeting products and to discuss their clinical application in the treatment and prevention of hypertrophic and keloid scars.

Nonsurgical management of hypertrophic scars: evidence-based therapies, standard practices, and emerging methods

Hypertrophic scars, resulting from alterations in the normal processes of cutaneous wound healing, are characterized by proliferation of dermal tissue with excessive deposition of fibroblast-derived extracellular matrix proteins, especially collagen, over long periods, and by persistent inflammation and fibrosis. Hypertrophic scars are among the most common and frustrating problems after injury. As current aesthetic surgical techniques become more standardized and results more predictable, a fine scar may be the demarcating line between acceptable and unacceptable aesthetic results. However, hypertrophic scars remain notoriously difficult to eradicate because of the high recurrence rates and the incidence of side effects associated with available treatment methods. This review explores the various treatment methods for hypertrophic scarring described in the literature including evidence-based therapies, standard practices, and emerging methods, attempting to distinguish those with clearly proven efficiency from anecdotal reports about therapies of doubtful benefits while trying to differentiate between prophylactic measures and actual treatment methods. Unfortunately, the distinction between hypertrophic scar treatments and keloid treatments is not obvious in most reports, making it difficult to assess the efficacy of hypertrophic scar treatment.

Abnormal scarring with keloid formation after osteochondroma excision in children with multiple hereditary exostoses

INTRODUCTION

Multiple hereditary exostoses (MHE) is an autosomal dominant condition characterized by numerous cartilage-capped exostoses/osteochondromas in areas of actively growing bone. Abnormal scarring with keloid formation after osteochondroma excision in children with MHE has not been previously described.

METHODS

A retrospective double-cohort study was undertaken to determine if children with MHE have a higher rate of abnormal scarring with keloid formation after osteochondroma excision when compared with those with solitary osteochondroma. In the initial phase, all consecutive children with MHE that underwent excision of osteochondroma with a minimum 2-year postoperative follow-up were identified. A control group of age-matched cases of solitary osteochondroma was subsequently identified. All patients were interviewed for wound healing problems and noncosmetic scarring. All patients with unsatisfactory scars were asked to send pictures and/or were invited for follow-up. Data were statistically analyzed.

RESULTS

Eighty-three surgeries were performed in 25 patients with MHE, whereas 25 surgeries were performed in 25 patients with solitary osteochondroma. Twelve keloid scars were noted in 7 patients with MHE, and no keloids were noted in any of the patients in the solitary group. Diagnosis of MHE was a statistically significant risk factor for formation of keloids after surgery (P < 0.05).

DISCUSSION

Abnormal scarring with keloid formation after osteochondroma excision in MHE has not been previously reported. Although this study has limited numbers, the results demonstrate a statistically significant correlation between keloid formation and MHE. The risk for abnormal scarring and keloid formation should be discussed with all patients before surgery.

The results of surgical excision and adjuvant irradiation for therapy-resistant keloids: a prospective clinical outcome study

BACKGROUND

There is no consensus on the best way to treat keloids, because adequate studies on this subject are sparse. Surgical excision in combination with radiotherapy is considered the most efficacious treatment available in severe keloids following the International Clinical Recommendations on Scar Management. Unfortunately, the recommendations are mainly based on retrospective studies that do not define recurrence.

METHODS

The authors evaluated the recurrence rate of therapy-resistant keloids treated with excision followed by radiotherapy (1200 Gy in three or four fractions). The minimum follow-up period was 12 months. The therapeutic outcome was judged as recurrence (elevation of the lesion not confined to the original wound area) or nonrecurrence. An evaluation of the outcome of the scars was obtained by using the Patient and Observer Scar Assessment Scale.

RESULTS

Twenty-one patients with 32 keloids were evaluated. The recurrence rate was 71.9 percent after a mean follow-up period of 19 months.

CONCLUSIONS

This high recurrence rate suggests that radiotherapy might be less efficacious than suggested by other studies. On the basis of the authors' results, surgical excision combined with radiotherapy should be reserved as a last resort in the treatment of therapy-resistant keloids.

Effect of Pulse Width of a 595-nm Flashlamp-Pumped Pulsed Dye Laser on the Treatment Response of Keloidal and Hypertrophic Sternotomy Scars

BACKGROUND

Flashlamp-pumped pulsed dye lasers (PDLs) have successfully treated keloidal and hypertrophic scars.

OBJECTIVE

The objective was to investigate the effect of pulse width of a PDL in treating keloidal and hypertrophic scars.

METHODS

On each of 19 patients, keloidal or hypertrophic median sternotomy scars were divided into two segments. Both segments on all patients were randomly treated with a 595-nm PDL at a fluence of 7 J/cm(2) and pulse widths of 0.45 and 40 ms to both segments, every 4 weeks for a total of three treatments. Scar volume, height, erythema, and pliability were measured at Weeks 0, 4, 8, and 24.

RESULTS

The volume of segments treated with 0.45- and 40-ms pulses decreased significantly after two treatments. Segments treated with a 0.45-ms pulse width showed significantly greater improvement than those treated with 40-ms pulses after three treatments. Elasticity of 0.45-ms segments was significantly higher than those of 40-ms segments, following two treatments. Pulse width had no significant effect in improvement of scar erythema.

CONCLUSIONS

A pulse width of 0.45 ms of PDL was more effective in decreasing scar size and improving scar pliability than that of 40 ms. A 595-nm PDL was safe and effective in treatment of hypertrophic scars and keloids in dark-skinned individuals. This study was supported in part by an educational grant from the Dermatological Society of Thailand.

Is the Treatment of Keloid Scars Still a Challenge in 2006?

BACKGROUND

Several options are described to treat keloid scars, none of them being 100% successful. Radiotherapy is suggested to have the most significant effect on recurrence rate.

OBJECTIVES

The aim of the study is to confirm the effectiveness of iridium brachytherapy combined with surgery and to evaluate patient satisfaction.

PATIENTS AND METHODS

We retrospectively enrolled 24 patients with 30 keloids, treated by surgical excision and iridium 192 high-dose-rate (HDR) brachytherapy.

RESULTS

We observed a significant difference in scar thickness before and after the treatment (P < 0.001). With regard to patient satisfaction and complaints, 79.1% of them had no pain and irritation after treatment, 79.2% of patients would recommend this treatment to other patients, and 87.5% would undergo this treatment again if necessary.

CONCLUSIONS

Our results confirm the effectiveness of surgical keloid excision followed by HDR brachytherapy in primary treatment or if other alternative methods have failed.

Laser treatment of keloids and hypertrophic scars

BACKGROUND

Lasers have been used in the treatment of hypertrophic scars and keloids for more than 20 years. Different laser systems have been examined; among them pulsed dye lasers are currently considered the laser of choice in these settings.

OBJECTIVES

The purpose of this study is to review the pertinent literature and provide updated information on different laser therapies available for treatment of keloids and hypertrophic scars.

METHODS

A Medline literature search was performed for relevant publications.

RESULTS

In this review the results of published studies in the treatment and prevention of hypertrophic scars and keloids are presented. Suggested mechanisms of action are reviewed. A review of the optimal laser parameters to modulate treatment outcome will be discussed. Different lasers are effective in not only the treatment but also the prevention of hypertrophic scars and keloids, among them PDL is more promising. Most of the suggested theories are based on the selective photothermolysis in which the light energy emitted from a vascular laser is absorbed by hemoglobin, generating heat and leading to coagulation necrosis, neocollagenesis, collagen fiber heating with dissociation of disulfide bonds and subsequent collagen fiber realignment.

CONCLUSION

The optimal laser is currently 585 nm PDL, although the recent results of Q-switched 532 nm frequency-doubled Nd:YAG are promising. Early use of lasers are beneficial, especially in those who are prone to develop these lesions.

Hyperplastische Narben und Keloide

Aberrant wound healing results in unsightly scarring, hypertrophic scarring, and keloid formation, causing functional and cosmetic deformities, discomfort, psychological stress, and patient dissatisfaction. Scar prevention and management continue to be important issues for the facial plastic surgeon. This article presents an overview on the pathogenesis of a scar and of the different types of scars. Differences between keloids, hypertrophic scars and normal scars include distinct scar appearance, histologic morphology and cellular function in response to growth factors. Recent advances in our understanding of the wound healing process reveal possible causes for hypertrophic scars and keloids. This information might assist in the development of efficacious prevention and treatment for hypertrophic scar and keloid formation. This article also describes the strategies available for scar prevention. Recommendations focus on the management of hypertrophic scars and keloids.

Transforming growth factor beta (TGFbeta) and keloid disease

Keloids are benign fibroproliferative diseases of unknown aetiology. They occur as a result of derangement of the normal wound healing process in susceptible individuals. Although several factors have been postulated in the aetiopathogenesis of this condition, there has been growing evidence to suggest a role for Transforming Growth Factor beta (TGFbeta) family members in its pathogenesis. TGFbeta has also been found to be associated with fibrotic diseases affecting different organs of the body including liver, kidney, lung as well as skin. In this review article, we will discuss the morphology and mechanism of action of TGFbeta and its isoforms and present the most up to date literature discussing the role of TGFbeta isoforms, their receptors, and intracellular signalling pathways (the SMAD pathway) in the pathogenesis of keloid disease. Understanding the role of TGFbeta in keloid disease could lead to the development of clinically useful therapeutic modalities for treatment of this condition.

Combined Therapy in the Treatment of Auricular Keloids

Management of earlobe keloids is still controversial. Many different treatment modalities have been employed; however, no single approach has been completely successful. We used combination therapy that included compression therapy, laser excision, and serial steroid injection, which has improved our therapeutic outcomes for earlobe keloids.

Epidemiology, aetiology and management of abnormal scarring: a review of the literature

Keloid and hypertrophic scars are the result of abnormal processes in scar formation. This paper reviews the literature and the many debates concerning the processes that cause abnormal scarring.

Hypertrophic Response and Keloid Diathesis: Two Very Different Forms of Scar

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Have a greater appreciation of the extent of differences and similarities between keloid and hypertrophic scarring. 2. Have a greater appreciation of the significance of the stage of maturation of a keloid or hypertrophic scar with regard to its morphologic, biochemical, and molecular profile. 3. More critically review basic science research that is based on poorly characterized scar tissue. 4. More critically review clinical studies that are based on poorly characterized scar tissue.

BACKGROUND

Hypertrophic and keloid scars remain extremely challenging, particularly in their variable response to treatment. The understanding of hypertrophic and keloid scarring is evolving from a position where they were regarded as different stages of the same process to the contemporary perspective of two separate entities. This article reviews the differences in the two forms of scarring and discusses the implications for future research.

METHODS

The authors conducted a MEDLINE search of all English language reviews linking key words "hypertrophic," "keloid," and "scarring."

RESULTS

Over the past four decades, there has been considerable clinical and experimental research looking at the biological nature and therapeutic response of keloid and hypertrophic scarring. As more differences are emerging regarding the fundamental biology of the scars, investigators are giving more detailed characterization of their source material. It is evident that even within the broad categories of hypertrophic and keloid scarring there is a heterogenous distribution of pathologic connective tissue matrix biology.

CONCLUSION

Considerable advances have been made in our understanding of the fundamental biology of scarring. As research methodology becomes even more sophisticated, it will be even more crucial to extensively characterize source material, recognizing major differences not only between keloid and hypertrophic scar but also between scars of varying stages of maturation and histomorphological, biochemical, and molecular variations within individual scars.

Erbium:YAG laser treatment of post-burn scars: potentials and limitations

Erbium:YAG lasers are successfully used to treat a variety of epidermal and dermal lesions, including rhytides, dyschromias, and certain types of scars. To date, however, no report has focused on the experiences with this laser in reconstructive burn surgery. Since 2001, the Erbium:YAG laser has become an integral part of the treatment of postburn scars at the Berlin Burn Center. This paper presents the techniques applied and clinical experiences obtained. In addition, a new stripe technique is introduced, which avoids healing disturbances in scars following deep burns. In conclusion, the Erbium:YAG laser has proven to be a valuable supplementary tool for the improvement of cosmetically disturbing mild postburn scars. It is particularly handy in areas difficult to treat, such as the eyes, nose, lips, and fingers. The individual advantages of the Erbium:YAG laser, other laser systems, and dermabrasion for the treatment of burn scars are compared in a brief survey.

Acne: treatment of scars

Acne is a common disease affecting a significant proportion of the population.(1-3) It causes considerable morbidity through soreness, disfigurement, and social handicap due to inflammatory lesions.(4,5) Modern therapy ensures that a considerable proportion of all patients can be offered effective treatment of their disease, but the morbidity is not restricted solely to the inflammatory lesions of acne.(6,7) Despite appropriate and effective primary prevention of scarring, scarring occurs in some degree in 95% of all patients irrespective of the severity of inflammatory acne (although severe acne causes more scarring than the milder forms). The scarring causes long-term morbidity that requires specific therapy.(7)

Mechanism of benign biliary stricture: A morphological and immunohistochemical study

AIM: To explore the mechanism of benign biliary stricture.

METHODS: A model of trauma of bile duct was established in 28 dogs. The anastomosed tissues were resected and examined by light and electron microscopes on day 3, in wk 1, 3 and mo 3, 6 after operation. CD68, TGF-β1 and α-SMA were examined by immunohistochemical staining, respectively.

RESULTS: The mucosal epithelium of the bile duct was slowly recovered, chronic inflammation lasted for a long time, fibroblasts proliferated actively, extracellular matrix was over-deposited. Myofibroblasts functioned actively and lasted through the whole process. The expression of macrophages in lamina propria under mucosa, TGF-β1 in granulation tissue, fibroblasts and endothelial cells of blood vessels, α-SMA in myofiroblasts were rather strong from the 1st wk to the 6th mo after operation.

CONCLUSION: The type of healing occurring in bile duct belongs to overhealing. Myofibroblasts are the main cause for scar contracture and stricture of bile duct. High expressions of CD68, TGF-β1 and α-SMA are closely related to the active proliferation of fibroblasts, extracellular matrix over-deposition and scar contracture of bile duct.

Keloid disease: clinical relevance of single versus multiple site scars

Much of our current understanding of keloid disease (KD) is based on anecdote rather than objective observation and statistical analysis. To elucidate further the aetiology of KD, we compared the profiles of patients with single versus multiple anatomical site keloid scars. We studied the clinical characteristics of 211 cases of keloid scarring, 137 (65%) females and 74 (35%) males. There were 122 cases with scars in single anatomical site and 89 cases with 369 scars in multiple anatomical sites entered into the study. Patients were of Afrocaribbean origin that presented to the department of Plastic and Reconstructive Surgery at the University of West Indies in Kingston, Jamaica. A total number of 491 keloid scars (single and multiple sites) were evaluated in the study. Data were collected on multiple parameters. The association of age of onset, anatomical area, cause of scarring, sex of the patient, presence or absence of family and medical history in patients with single as opposed to multiple site keloid scars were examined in detail and statistically evaluated. The formation of keloid scars in multiple anatomical sites was found to be statistically significant in that it was more common in younger age groups (p < 0.001) and in females (p < 0.001). Previous medical history, including other fibrotic disorders, was not statistically associated with development of keloid scars in multiple anatomical sites (p > 0.05). More than 50% (111) of all keloid cases had a positive family history of keloid scarring, and family history was strongly associated with the formation of keloid scars in multiple sites as opposed to a single anatomical site (p < 0.002). We conclude that in this particular study group female sex, younger age at presentation and the presence of a positive family history were associated with the development of keloid scars in multiple anatomical sites in Afrocaribbean individuals. This knowledge further emphasizes the need for genetic studies in KD, which may lead to better diagnostic and therapeutic regimes.

Histopathological Differential Diagnosis of Keloid and Hypertrophic Scar

Distinguishing hypertrophic scar (HS) from keloid histopathologically is sometimes difficult because thickened hyalinized collagen (keloidal collagen), the hallmark of keloid, is not always detectable and alpha-smooth muscle actin (alpha-SMA), a differentiating marker of HS, is variably expressed in both forms of scar. The aim of this study was to investigate additional distinguishing features to facilitate differentiation between keloid and HS. We compared various histologic features and the expression of alpha-SMA in 40 specimens of keloid and 10 specimens of HS. The features more commonly seen in keloids were: (a) no flattening of the overlying epidermis, (b) no scarring of the papillary dermis, (c) presence of keloidal collagen, (d) absence of prominent vertically oriented blood vessels, (e) presence of prominent disarray of fibrous fascicles/nodules, (f) presence of a tongue-like advancing edge underneath normal-appearing epidermis and papillary dermis, (g) horizontal cellular fibrous band in the upper reticular dermis, and (h) prominent fascia-like fibrous band. The last three features were found in keloid specimens only, including the ones lacking detectable keloidal collagen. Our study confirmed the diagnostic value of keloidal collagen, but it was only found in 55% of keloid specimens. Alpha-SMA expression was found in both HS (70%) and keloid (45%), thus it would not be a differentiating marker. In scars with no detectable keloidal collagen, the presence of the following feature(s) favors the diagnosis of keloid: non-flattened epidermis, non-fibrotic papillary dermis, a tongue-like advancing edge, horizontal cellular fibrous band in the upper reticular dermis, and prominent fascia-like band.

Description of site-specific morphology of keloid phenotypes in an Afrocaribbean population

By examining the keloid scars of 211 Afrocaribbean patients presenting to the Plastic Surgery unit in Kingston, Jamaica, we have described site-specific morphologies of scarring; keloid disease is not a homogenous biological entity. All cases conformed to clinical criteria for diagnosis of keloid scarring: 369 keloid scars were present in 137 females (2-83 years; mean 29.6 years; SD+/-14.9 years) and 74 males (5-90 years, mean 29.5 years; SD+/-15.0 years). Morphologies were specific to each anatomical site: trunk scars (n=45,12.1%) were geometrically shaped with clear margins or irregular in outline, surface and margin; back single scars were well-demarcated botryoid but multiple scars were butterfly-shaped, spheroidal and irregular; chest scars (n=72,20.1%) were butterfly or nonbutterfly shaped found most commonly in the midsternal line; upper limb scars (n=57,15.3%) mostly in the deltoid region (propeller shaped) or elsewhere nodular, linear to irregular; ear (n=85,23%) commonest site being the lobe, having reniform to bulbous shape; face and neck (n=60,16.2%) scars were firm nodular to hard; posterior auricular scars were either horizontal and oblong-shaped or vertical and reniform in outline; scalp scars (n=11,2.8%) were commonest in the occipital area varying from small papules to large plaques; lower limb scars (n=39,10.5%) varied from propeller, butterfly, petalloid to dum-bell-shaped. Three plantar and eight pubic keloids were rare findings. Recognition of different morphological phenotypes is necessary in understanding genotypic predisposition and aiding diagnosis, treatment and prognosis of keloid scars.