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

Familial Spontaneous Keloids: Examining Thoracic Manifestations in Two Brothers

Keloids are complex fibroproliferative disorders with diverse clinical presentations. Spontaneous keloids (SKs) represent a rare subtype that emerges without any known preceding traumatic event. This report presents a case of familial spontaneous keloids appearing on the thoracic region in two brothers with no prior history of trauma or keloid occurrence in other family members. The lesions exhibited progressive growth over several years but responded to cycles of triamcinolone treatment. This case underscores an unusual spontaneous occurrence of keloids in the thoracic region of two siblings, highlighting the potential genetic predisposition in the aetiology of these lesions. Additionally, this instance reinforces the concept that keloids can develop spontaneously without any apparent trauma in the affected area.

Development and validation of novel keloid-derived immortalized fibroblast cell lines

Keloids are a common connective tissue disorder with an ill-understood etiopathogenesis and no effective treatment. This is exacerbated because of the absence of an animal model. Patient-derived primary keloid cells are insufficient as they age through passaging and have a limited supply. Therefore, there is an unmet need for development of a cellular model that can consistently and faithfully represent keloid's pathognomic features. In view of this, we developed keloid-derived immortalized fibroblast (KDIF) cell lines from primary keloid fibroblasts (PKF) by transfecting the human telomerase reverse transcriptase (hTERT) gene. The TERT gene encodes the catalytic subunit of the telomerase enzyme, which is responsible for maintaining the cellular replicative potential (cellular immortalization). Primary fibroblasts from keloid-specific lesional (peripheral, middle, and top) as well as extralesional sites were isolated and evaluated for cell line development and comparative cellular characteristics by employing qRT-PCR and immunofluorescence staining. Moreover, the immortalized behavior of KDIF cell lines was evaluated by comparing with cutaneous fibrosarcoma and dermatofibrosarcoma protuberans cell lines. Stable KDIF cell lines with elevated expression of hTERT exhibited the cellular characteristics of site-specific keloid fibroblasts. Histochemical staining for β-galactosidase revealed a significantly lower number of β-gal-positive cells in all three KDIF cell lines compared with that in PKFs. The cell growth curve pattern was studied over 10 passages for all three KDIF cell lines and was compared with the control groups. The results showed that all three KDIF cell lines grew significantly faster and obtained a fast growing characteristic as compared to primary keloid and normal fibroblasts. Phenotypic behavior in growth potential is an indication of hTERT-mediated immortalized transformation. Cell migration analysis revealed that the top and middle KDIF cell lines exhibited similar migration trend as site-specific PKFs. Notably, peripheral KDIF cell line showed significantly enhanced cell migration in comparison to the primary peripheral fibroblasts. All KDIF cell lines expressed Collagen I protein as a keloid-associated fibrotic marker. Functional testing with triamcinolone inhibited cell migration in KDIF. ATCC short tandem repeat profiling validated the KDIF as keloid representative cell line. In summary, we provide the first novel KDIF cell lines. These cell lines overcome the limitations related to primary cell passaging and tissue supply due to immortalized features and present an accessible and consistent experimental model for keloid research.

Effective keloid management using a combinatorial continuous-wave and repeat fractionated ablative CO2 laser regimen

BACKGROUND

Keloids are benign proliferative scars that form as a result of dysregulated growth and collagen deposition in response to cutaneous injury. Laser therapies have emerged as promising options for the treatment of keloids, with performance varying by laser type and lesion characteristics.

PURPOSE

To assess the combined continuous wave and repetitive fractionated CO2 laser treatment of keloids.

METHODS

A retrospective chart review of 22 cases of keloid scars treated with combined CO2 laser modes. A single session of continuous wave followed by five sessions of fractional delivery. Efficacy was assessed using the Patient and Observer Scar Assessment Scale (POSAS) and the Vancouver Scar Scale. The Numeric Rating Scale was used to assess patient satisfaction and pain.

RESULTS

Most patients were female (77.3%) with skin type IV (72.7%), age was 24.3 ± 9.3 years, most keloids were located on the earlobe (56.5%) or arm or hand (17.4%), size ranged from 5 to 10 cm, and time since injury ranged from 3 months to 35 years. No serious adverse events were reported. At 6 months, significant improvements from baseline occurred in all characteristics, scar color (4.8 ± 2.8 to 1.9 ± 1.1), rigidity (5.0 ± 2.8 vs. 5.4 ± 2.8), thickness (5.4 ± 2.8 vs. 2.0 ± 1.1), and irregularity (5.9 ± 2.4 vs. 1.9 ± 0.9). The Vancouver scores followed a similar trend. Patient-rated overall improvement from 37 ± 17.6 at baseline to 16.1 ± 8.5 at 6 months, and improvement in associated pain and pruritus.

CONCLUSION

Combination of two ablative laser delivery modes within a single laser platform provided for effective and safe keloid management and left patients highly satisfied.

A Working Classification and a Simple Effective Management Protocol for Ear Keloids

BACKGROUND

The unpredictable behavior of scars in the ear makes it a nightmare in planning the management protocol for ear keloids. To understand and classify the ear keloid, a simple working classification based on the anatomical location has been proposed. Low recurrence rate should be the primary determinant in choosing a management protocol. The scar control protocol includes complete excision of the keloid, taking care not to extend to normal skin which was followed by a round-the-clock 24×7 management protocol for 6 months to 1 year.

PATIENTS AND METHODS

This study presents a prospective analysis of 71 patients with 106 ear keloids who underwent surgery in our clinic between 2007 and 2022. The management included complete excision, postoperative adjuvant therapy in the form of self-managed scar stabilization with bi-digital, bi-dimensional, bi-directional massage and corticosteroid therapy if warranted. Complete keloid excision with primary reconstruction was followed up to 1 year, and recurrence rates were tracked during this period.

RESULTS

Of the 71 patients, 91.54% were women. All lesions (n = 106) were treated by complete excision. The average age was between 15 and 30 years. The overall recurrence rate was 5.6%.

CONCLUSION

With our classification and protocol, we were able to achieve a consistent recurrence free state in 94.4% of patients.

LEVEL OF EVIDENCE IV

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 .

TGF-β Isoforms Affect the Planar and Subepithelial Fibrogenesis of Human Conjunctival Fibroblasts in Different Manners

Three highly homologous isoforms of TGF-β, TGF-β-1~3, are involved in the regulation of various pathophysiological conditions such as wound healing processes in different manners, despite the fact that they bind to the same receptors during their activation. The purpose of the current investigation was to elucidate the contributions of TGF-β-1 ~3 to the pathology associated with conjunctiva. For this purpose, the biological effects of these TGF-β isoforms on the structural and functional properties of two-dimensional (2D) and three-dimensional (3D) cultured human conjunctival fibroblasts (HconF) were subjected to the following analyses: 1) transendothelial electrical resistance (TEER), a Seahorse cellular metabolic measurement (2D), size and stiffness measurements of the 3D HTM spheroids, and the qPCR gene expression analyses of extracellular matrix (ECM) components (2D and 3D). The TGF-β isoforms caused different effects on the proliferation of the HconF cell monolayer evaluated by TEER measurements. The differences included a significant increase in the presence of 5 ng/mL TGF-β-1 and -2 and a substantial decrease in the presence of 5 ng/mL TGF-β-3, although there were no significant differences in the response to the TGF-β isoforms for cellular metabolism among the three groups. Similar to planar proliferation, the TGF-β isoforms also induced diverse effects toward the mechanical aspects of 3D HconF spheroids, where TGF-β-1 increased stiffness, TGF-β-2 caused no significant effects, and TGF-β-3 caused the downsizing of the spheroids and stiffness enhancement. The mRNA expression of the ECMs were also modulated in diverse manners by the TGF-β isoforms as well as the culture conditions for the 2D vs. 3D isoforms. Many of these TGF-β-3 inducible effects were markedly different from those caused by TGF-β1 and TGF-β-2. The findings presented herein suggest that the three TGF-β isoforms induce diverse and distinctly different effects on cellular properties and the expressions of ECM molecules in HconF and that these changes are independent of cellular metabolism, thereby inducing different effects on the epithelial and subepithelial proliferation of human conjunctiva.

Evaluation of the Risk of Hypertrophic Scarring and Keloid Following Eyelid Procedures: A Systematic Review

BACKGROUND

Eyelid surgeries are common operations performed for both cosmetic and functional purposes. Because the periorbital region is highly visible, it is important to avoid poor scar formation in this cosmetically sensitive region. No study to date has investigated the possible existence of keloid formation following eyelid procedures.

OBJECTIVES

This study systematically reviewed the literature to identify cases of hypertrophic scar and keloid formation following cosmetic or functional (nonburn) eyelid procedures to aid surgeons when counseling patients.

METHODS

A PubMed/MEDLINE search was conducted on May 17, 2022, using appropriate search terms: "blepharoplasty," "tarsorrhaphy," "canthotomy," "ptosis repair," "epicanthoplasty," "keloid," "hypertrophic scar," and related lay terms. All eligible articles in English with no lower date limit were included for analysis. Descriptive statistics, exclusion criteria, and summarized results are reported.

RESULTS

The PubMed search yielded 107 abstracts/articles. Full-text review resulted in 34 articles included for analysis. Twenty manuscripts reported no occurrences of hypertrophic scars. Only 13 manuscripts reported patients with hypertrophic scarring, which equated to 36 patients out of 3650. One individual was identified in a series of 77 patients who developed a keloid after a tarsorrhaphy. No articles reported a keloid as an outcome of strictly cosmetic procedures.

CONCLUSIONS

This study concludes that there are no reported instances of keloid formation following cosmetic (nonburn) eyelid procedures in the existing literature. Hypertrophic scar formation is minimally reported. The absence of keloid scar formation on the eyelid is critical knowledge for surgeons when educating patients about maladaptive scarring risks following eyelid procedures.

LEVEL OF EVIDENCE: 4

Evidence of inter- and intra-keloid heterogeneity through analysis of dermal fibroblasts: A new insight in deciphering keloid physiopathology

Keloid scars are hypertrophic and proliferating pathological scars extending beyond the initial lesion and without tendency to regression. Usually, keloids are considered and treated as a single entity but clinical observations suggest heterogeneity in keloid morphologies with distinction of superficial/extensive and nodular entities. Within a keloid, heterogeneity could also be detected between superficial and deep dermis or centre and periphery. Focusing on fibroblasts as main actors of keloid formation, we aimed at evaluating intra- and inter-keloid fibroblast heterogeneity by analysing their gene expression and functional capacities (proliferation, migration, traction forces), in order to improve our understanding of keloid pathogenesis. Fibroblasts were obtained from centre, periphery, papillary and reticular dermis from extensive or nodular keloids and were compared to control fibroblasts from healthy skin. Transcriptional profiling of fibroblasts identified a total of 834 differentially expressed genes between nodular and extensive keloids. Quantification of ECM-associated gene expression by RT-qPCR brought evidence that central reticular fibroblasts of nodular keloids are the population which synthesize higher levels of mature collagens, TGFβ, HIF1α and αSMA as compared to control skin, suggesting that this central deep region is the nucleus of ECM production with a centrifuge extension in keloids. Although no significant variations were found for basal proliferation, migration of peripheral fibroblasts from extensive keloids was higher than that of central ones and from nodular cells. Moreover, these peripheral fibroblasts from extensive keloids exhibited higher traction forces than central cells, control fibroblasts and nodular ones. Altogether, studying fibroblast features demonstrate keloid heterogeneity, leading to a better understanding of keloid pathophysiology and treatment adaptation.

Keloid disease: Review with clinical atlas. Part I: Definitions, history, epidemiology, clinics and diagnosis

Keloids are chronic progressive dermal pseudo-tumors that can grow considerably in volume and surface area but do not invade other tissues. They are usually triggered by dermal injury or inflammation, but they are not scars in the normal sense of the word, since they enlarge and progress over decades. The phenomenon usually referred to as "hypertrophic scars" represents a kind of keloidal process that does not extend beyond the initial site of injury and spontaneously regresses in 12-24 months. The multiplication of keloids and hypertrophic scars in a single patient is known as keloid disease. Keloid disease is due to a familial predisposition (autosomal dominant) that preferentially affects people of non-European ancestry, especially those of sub-Saharan African descent. Keloid disease has a deep impact on quality of life, not only because of disfiguring lesions, but also because of the frequency of associated intense neurogenic pruritus and pain, as well as recurrent bouts of suppuration. Diagnosis relies primarily on a good knowledge of the clinical characteristics of keloids, thus warranting the inclusion of a clinical atlas in the first part of the review. The second part will deal with the pathology, pathophysiology and treatment of keloid disease.

Combination cryotherapy and intralesional corticosteroid versus steroid monotherapy in the treatment of keloids

BACKGROUND

Keloids are common and have significant negative effects on quality of life. There is a need for more effective treatment approaches for keloids.

AIMS

We investigated treatment outcomes of intralesional triamcinolone acetonide (IL TAC) compared with combination IL TAC and cryotherapy, including changes in pruritus, pain, and keloid size.

PATIENTS/METHODS

We performed a prospective study of patients referred to one provider who treated patients with combination therapy and compared them to a historic control cohort treated with IL TAC alone. All patients were seen at Thomas Jefferson University between 2019 and 2021. Patient demographics, location of keloids, and inciting events were recorded. Pruritus and pain scores were self-reported by patients using a 10-point Likert scale administered as standard of care. Changes in keloid size were denoted as "No change," "up to 50% decrease," "more than 50% decrease," and "completely flattened."

RESULTS

While both treatments produced a significant reduction in mean pruritus and pain scores, there was no difference between the two treatment groups (p = 0.3933 and p = 0.2123, respectively). A greater percentage of keloids in the combination therapy group had a post-treatment size difference greater than 50% compared with those in the IL TAC only treatment group (p = 0.0021). In the subgroup of pubic keloids, all lesions treated with combination IL TAC and cryotherapy responded remarkably well to treatment.

CONCLUSIONS

While both IL TAC and IL TAC with cryotherapy were effective at reducing pruritus and pain, combination therapy was more effective in reducing keloid size, specifically for pubic keloids.

Single-cell RNA-seq reveals the communications between extracellular matrix-related components and Schwann cells contributing to the earlobe keloid formation

Keloid is a major type of skin fibrotic disease, with one prominent feature of extensive accumulation of extracellular matrix (ECM) components, and another feature of pain/itching, which is closely related to the peripheral nervous system (PNS). However, the molecular pathogenesis of these two prominent features still needs to be further explored. In the present study, we performed single-cell RNA sequencing (scRNA-seq) on clinical earlobe keloid samples and adjacent normal skin samples and constructed a keloid atlas of 31,379 cells. All cells were clustered into 13 major cell types using cell-type-specific markers. Among them, fibroblast, vascular endothelial cells, and smooth muscle cells were defined as the ECM-related populations according to their ECM-associated functions. Also, we found that Schwann cells (SCs) were the main neuron cells of PNS in the skin. Interestingly, the cell proportions of ECM-related populations, as well as SC were increased significantly in the earlobe keloid compared to the adjacent normal tissues, suggesting an important role of these cell types in the development of the earlobe keloid. Comprehensive cell-cell interaction analysis at the single-cell level revealed a strong interaction between SC and ECM-related subgroups which might be mediated by SEMA3C signaling pathways and MK/PTN gene family, which are found to be mainly involved in promoting cell proliferation and migration. Moreover, further exploration of the interactions of ECM-related populations and SC in different keloids, including earlobe keloid, back keloid, and chest keloid revealed an increasing amount of TGFβ-TGFβ receptor interactions in chest/back keloids as compared to earlobe keloid, which suggested the anatomic site-specific pathogenesis in different keloids. Altogether, these findings suggested the interactions between ECM-related populations and SC contributing to the earlobe keloid formation and helped us to better understand the pathogenesis of keloids.

Quality-of-life of people with keloids and its correlation with clinical severity and demographic profiles

Though the impairment of quality of life in individuals with keloids is profound, it has neither been well quantified nor correlated with severity in people with skin of colour. This cross-sectional, questionnaire-based study comprised 110 patients with keloid(s). A physician measured the severity of keloids using the Vancouver Scar scale and impairment of quality of life using the patient-filled Hindi version of Dermatology Life Quality Index questionnaire. The relationship among QoL and severity score as well as with components of demographic data was analysed using SPSS. Our study found the severity of keloid(s) to be moderately but significantly correlated with the quality of life of its sufferers. Individuals with multiple keloids were found to be significantly younger than those with solitary ones. Itching, pain, along with restricted mobility significantly impacted the quality of life as well as severity of keloids. Individuals who had undergone prior treatment were found to have a worse quality of life than the treatment naive. Recurrence was found to be associated with lower scar severity, multiple keloids, and younger age. Increasing age, though associated with greater scar severity, lacked any relationship with the quality of life. Our study also found that individuals with bigger keloids sought treatment earlier and more often. Hyperpigmented keloid(s), more common in individuals with skin of colour, were associated with a significantly worse quality of life as well as a higher scar severity.

Pediatric earlobe keloids: Outcomes and patterns of recurrence

PURPOSE

Keloids occur as a result of abnormal wound healing and as many as 70% of keloids and hypertrophic scars affect the pediatric population. Earlobe keloids, similar to lesions elsewhere in the body, remain a challenging problem given the high rates of recurrence and lack of consensus regarding treatment strategy. This study aims to evaluate the outcomes and patterns of recurrences following treatment of earlobe keloids in a large cohort of pediatric patients to facilitate identification of the optimal treatment strategy.

METHODS

All pediatric patients who underwent surgical therapy for earlobe keloids over a 10-year period (2004-2015) were identified and demographic, clinical and outcomes data were collected. A follow-up phone survey was administered to assess rates of long-term recurrence and overall satisfaction with the treatment strategy. Data analysis was performed using Student's t-test and Fisher's exact as appropriate.

RESULTS

A total of 94 patients with 135 keloids were identified. Mean age was 14 years with slight preponderance of females (52%) and a majority (75%) of the patients were African American (AA). Mean keloid size was 2.4 cm (0.25-11 cm) with ear piercing being the most common inciting etiology. Excision with steroid injection (59%) was the most frequent treatment approach followed by excision alone (25%). During a median follow up of 2 years, keloid recurrence occurred in 27 (28.7%) patients, 19 (70.4%) underwent additional therapy with 10 (52.6%) re-recurrences noted. Median time to recurrence was 23 months, with a slightly higher recurrence rate in AA patients (32%; p = 0.26) and in those age < 10 years (50%; p = 0.11).

CONCLUSION

This represents the largest series of earlobe keloids treatment in children. Our data suggest that recurrence rates are unaffected by the age at excision and race of the patient. Moreover, adjuncts to excisional therapy such as steroid injection, compression therapy and radiation also did not appear to influence recurrence. Given the pattern of recurrences studies with longer term follow-up are needed to assess the efficacy of treatment strategies.

TYPE OF STUDY

Case series.

LEVEL OF EVIDENCE

IV.

Keloid pathophysiology: fibroblast or inflammatory disorders?

Background

Keloids are defined as a benign dermal fibroproliferative disorder with no malignant potential. They tend to occur following trivial trauma or any form of trauma in genetically predisposed individuals. Keloids are known to grow beyond the margins of the wound and are common in certain body parts. The pathophysiology of keloid remains unclear, and fibroblasts have been presumed to be the main cells involved in keloid formation. Understanding the mechanism(s) of keloid formation could be critical in the identification of novel therapeutic regimen for the treatment of the keloids.

Objective

To review the pertinent literature and provide updated information on keloid pathophysiology.

Data Source

A Medline PubMed literature search was performed for relevant publications.

Results

A total of 66 publications were retrieved, with relevant publications on the etiology and pathogenesis as well as experimental studies on keloids. All articles were critically analyzed, and all the findings were edited and summarized.

Conclusion

There is still no consensus as on what is the main driving cell to keloid formation. One may, however, hypothesize that keloid formation could be a result of an abnormal response to tissue injury, hence resulting in an exaggerated inflammatory state characterized by entry of excessive inflammatory cells into the wound, including macrophages, lymphocytes, and mast cells. These cells seem to release cytokines including transforming growth factor β1 that stimulate fibroblasts to synthesize excess collagen, which is a hallmark of keloid disease.

Understanding Keloid Pathobiology From a Quasi-Neoplastic Perspective: Less of a Scar and More of a Chronic Inflammatory Disease With Cancer-Like Tendencies

Keloids are considered as benign fibroproliferative skin tumors growing beyond the site of the original dermal injury. Although traditionally viewed as a form of skin scarring, keloids display many cancer-like characteristics such as progressive uncontrolled growth, lack of spontaneous regression and extremely high rates of recurrence. Phenotypically, keloids are consistent with non-malignant dermal tumors that are due to the excessive overproduction of collagen which never metastasize. Within the remit of keloid pathobiology, there is increasing evidence for the various interplay of neoplastic-promoting and suppressing factors, which may explain its aggressive clinical behavior. Amongst the most compelling parallels between keloids and cancer are their shared cellular bioenergetics, epigenetic methylation profiles and epithelial-to-mesenchymal transition amongst other disease biological (genotypic and phenotypic) behaviors. This review explores the quasi-neoplastic or cancer-like properties of keloids and highlights areas for future study.

Hyperbaric oxygen therapy can ameliorate the EMT phenomenon in keloid tissue

BACKGROUND

Hyperbaric oxygen therapy (HBOT) has been widely used in the clinical setting. In this study, HBOT therapy was evaluated for its ability to ameliorate the epithelial-to-mesenchymal transition (EMT) phenomenon in keloid tissue.

METHODS

Keloid patients were randomly divided into two groups: keloid patients (K group, 9 patients) and keloid patients receiving HBOT (O group, 9 patients). A third group with normal skin (S group, 9 patients) was established for control. Before HBOT and surgery, a laser Doppler flowmeter was used to measure the keloid blood supply of patients in the O group. Hematoxylin and eosin (H&E) staining was used to observe morphology. E-cadherin, ZO-1, vimentin, fibronectin, vascular endothelial growth factor (VEGF), and hypoxia inducible factor (HIF)-1α were measured by immunofluorescence staining and Western blot analysis. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to evaluate the mRNA expression level of these factors as well.

RESULTS

In the O group, keloid blood perfusion was significantly reduced after patients received HBOT. Compared with the K group, lower expression levels of vimentin, vibronectin, VEGF, and HIF-1α were observed in the O group, whereas the expression of E-cadherin and ZO-1 was significantly higher. The mRNA expression of E-cadherin and ZO-1 was also increased after HBOT.

CONCLUSIONS

The expression levels of factors related to the EMT phenomenon were significantly reversed in keloid patients after they received HBOT, indicating that HBOT may be an effective therapy against the EMT phenomenon in keloid patients.

Easing the Excision of Earlobe Keloid

Earlobe keloids are commonly encountered in this era where ear piercing is routine in various traditions. Various medical and surgical methods have been tried for its management. Surgically, fillet flap surgery has better acceptability worldwide. Various difficulties are faced during keloid excision, and we hereby describe few innovative modifications (use of needle, hydrodissection, pressure dressing, bolster button) using cost-effective and simple materials (needles, dynaplast, buttons) to ease the excision of keloids. These have easy adaptability and also reduce the recurrence rate of earlobe keloids.

Fibroblast heterogeneity: implications for human disease

Fibroblasts synthesize the extracellular matrix of connective tissue and play an essential role in maintaining the structural integrity of most tissues. Researchers have long suspected that fibroblasts exhibit functional specialization according to their organ of origin, body site, and spatial location. In recent years, a number of approaches have revealed the existence of fibroblast subtypes in mice. Here, we discuss fibroblast heterogeneity with a focus on the mammalian dermis, which has proven an accessible and tractable system for the dissection of these relationships. We begin by considering differences in fibroblast identity according to anatomical site of origin. Subsequently, we discuss new results relating to the existence of multiple fibroblast subtypes within the mouse dermis. We consider the developmental origin of fibroblasts and how this influences heterogeneity and lineage restriction. We discuss the mechanisms by which fibroblast heterogeneity arises, including intrinsic specification by transcriptional regulatory networks and epigenetic factors in combination with extrinsic effects of the spatial context within tissue. Finally, we discuss how fibroblast heterogeneity may provide insights into pathological states including wound healing, fibrotic diseases, and aging. Our evolving understanding suggests that ex vivo expansion or in vivo inhibition of specific fibroblast subtypes may have important therapeutic applications.

Different properties of skin of different body sites: The root of keloid formation?

The purpose of this study was to examine extracellular matrix composition, vascularization, and immune cell population of skin sites prone to keloid formation. Keloids remain a complex problem, posing esthetical as well as functional difficulties for those affected. These scars tend to develop at anatomic sites of preference. Mechanical properties of skin vary with anatomic location and depend largely on extracellular matrix composition. These differences in extracellular matrix composition, but also vascularization and resident immune cell populations might play a role in the mechanism of keloid formation. To examine this hypothesis, skin samples of several anatomic locations were taken from 24 human donors within zero to 36 hours after they had deceased. Collagen content and cross-links were determined through high-performance liquid chromatography. The expression of several genes, involved in extracellular matrix production and degradation, was measured by means of real-time PCR. (Immuno)histochemistry was performed to detect fibroblasts, collagen, elastin, blood vessels, Langerhans cells, and macrophages. Properties of skin of keloid predilections sites were compared to properties of skin from other locations (nonpredilection sites [NPS]). The results indicated that there are site specific variations in extracellular matrix properties (collagen and cross-links) as well as macrophage numbers. Moreover, predilection sites (PS) for keloid formation contain larger amounts of collagen compared to NPS, but decreased numbers of macrophages, in particular classically activated CD40 positive macrophages. In conclusion, the altered (histological, protein, and genetic) properties of skin of keloid PS may cause a predisposition for and contribute to keloid formation.

Identification of ASAH1 as a susceptibility gene for familial keloids

Keloids result from abnormal proliferative scar formation with scar tissue expanding beyond the margin of the original wound and are mostly found in individuals of sub-Saharan African descent. The etiology of keloids has not been resolved but previous studies suggest that keloids are a genetically heterogeneous disorder. Although possible candidate genes have been suggested by genome-wide association studies using common variants, by upregulation in keloids or their involvement in syndromes that include keloid formation, rare coding variants that contribute to susceptibility in non-syndromic keloid formation have not been previously identified. Through analysis of whole-genome data we mapped a locus to chromosome 8p23.3-p21.3 with a statistically significant maximum multipoint LOD score of 4.48. This finding was followed up using exome sequencing and led to the identification of a c.1202T>C (p.(Leu401Pro)) variant in the N-acylsphingosine amidohydrolase (ASAH1) gene that co-segregates with the keloid phenotype in a large Yoruba family. ASAH1 is an acid ceramidase known to be involved in tumor formation by controlling the ratio of ceramide and sphingosine. ASAH1 is also involved in cell proliferation and inflammation, and may affect the development of keloids via multiple mechanisms. Functional studies need to clarify the role of the ASAH1 variant in wound healing.

Clinical implications of single- versus multiple-site keloid disorder: a retrospective study in an Asian population

BACKGROUND

There is strong evidence of genetic susceptibility in individuals with keloid disorder. The purpose of this cross-sectional study was to determine the clinical relevance of our proposed variables on the multiplicity of keloids by further investigating the presence of other keloids and a family history.

METHODS

This was a retrospective review, using institutional review board-approved questionnaires, of patients with keloids who were seen at Kangbuk Samsung Hospital between December 2002 and February 2010. Eight hundred sixty-eight patients were included in our study. Comparisons between the 2 groups were made using Mann-Whitney tests for continuous variables and χ2 tests for categorical variables.

RESULTS

In our patient group, younger age of onset and the presence of family history were significantly associated with the occurrence of keloids at multiple sites. The locations of extra-auricular keloids, in order of frequency, included the shoulder; anterior chest, including the breasts; deltoid; trunk and pubic area; upper extremities; lower extremities; and other sites. As compared to secondary keloids, primary keloids were significantly associated with both a lower degree of recurrence and the presence of other keloids. The presence or absence of family history was significantly associated with the presence or absence of other keloids and primary or secondary keloids.

CONCLUSIONS

Keloid disorder is one of the most frustrating problems in wound healing and advances in our understanding of the differences of occurrence at a single site versus multiple sites might help in understanding pathogenesis and improving treatment.

Identification of biomarkers involved in differential profiling of hypertrophic and keloid scars versus normal skin

Among raised dermal scar types, keloid (KS) and hypertrophic scars (HS) are considered to present clinical similarities, but there are no known specific biomarkers that allow both scar types to be easily distinguished. Development and progression of raised dermal scars comprises the activation of several molecular pathways and cell defence mechanisms leading to elevated extracellular matrix component synthesis, delayed apoptosis, altered migration and differentiation. Therefore, the aim here was to identify biomarkers that may differentiate between KS and HS compared to normal skin (NS). To achieve this aim, NS (n = 14), KS (n = 14) and HS (n = 14) biopsies were evaluated using histology by H&E staining. Tissue biopsies and primary fibroblasts (passages 0-4) were employed to assess the gene expression levels of 21 biomarkers selected from our previous microarray studies using qRT-PCR. Finally, protein expression was evaluated using In-Cell Western Blotting in primary fibroblasts (p 0-4). Our results demonstrated that out of the 21 biomarkers screened at mRNA and protein levels, α2β1-integrin, Hsp27, PAI-2, MMP-19 and CGRP showed significantly higher expression (p < 0.05) in KS compared to NS and HS. Additionally, these five key biomarkers were found to be significantly higher (p < 0.05) at mRNA level in KS taken from the sternum, a region known to be subjected to high mechanical forces in the body during the performance of daily movements. In conclusion, our findings offer potential molecular targets in raised dermal scars differentiation. Future targeted research may allow provision of diagnostic and prognostic markers in keloid versus hypertrophic scars.

Clinical and epidemiological analysis of keloids in Chinese patients

Keloids are common abnormally raised fibroproliferative lesions that can occur following even minor cutaneous trauma. There are limited data on Chinese patients with keloids, and the purpose of our study was to investigate the clinical and epidemiological features of keloids in Chinese patients. Assessment was performed by unified, designed questionnaires. A total of 715 patients were enrolled and statistical analysis and heritability were performed using EPI INFO 6.0, SPSS13.0 and Falconer's method. Keloids occurred typically between the ages of 10 and 30 years, and the mean age of initial onset was 21.14 ± 13.45 years in females and 22.55 ± 11.36 years in males. The difference in the mean age of onset was not significant between males and females (p > 0.05). A greater severity of keloids was observed in the positive history family group than in the negative history family group, and this difference was statistically significant (χ (2) = 10.889, p < 0.05). The formation of keloids in multiple anatomical sites was found to be significant in the positive family history group. This difference was statistically significant (χ (2) = 15.47, p < 0.001). The prevalence of keloids in first-, second- and third-degree relatives of the proband with keloids was 7.62, 0.38 and 0.035 %, respectively. These results were higher than those in controls and the difference of the prevalence rates of first- and second-degree relatives between probands and controls was significant (χ (2) = 224.63 and 12.078, respectively, p < 0.001). The heritability of keloids in first-, second- and third-degree relatives was 72.45, 40.55 and 17.07 %, respectively. Our findings revealed that the most severe forms of keloids were observed in the probands with positive family history, and the heritability in first-degree relatives of probands was 72.45 %. It is certain, therefore, that genetic factors play a role in the hereditary composition of keloids.

Keloids in Rubinstein-Taybi syndrome: a clinical study

BACKGROUND

Rubinstein-Taybi syndrome (RSTS) is a multiple congenital anomalies-intellectual disability syndrome. One of the complications is keloid formation. Keloids are proliferative fibrous growths resulting from excessive tissue response to skin trauma.

OBJECTIVES

To describe the clinical characteristics of keloids in individuals with RSTS reported in the literature and in a cohort of personally evaluated individuals with RSTS.

PATIENTS AND METHODS

We performed a literature search for descriptions of RSTS individuals with keloids. All known individuals with RSTS in the Netherlands filled out three dedicated questionnaires. All individuals with (possible) keloids were personally evaluated. A further series of individuals with RSTS from the U.K. was personally evaluated.

RESULTS

Reliable data were available for 62 of the 83 Dutch individuals with RSTS and showed 15 individuals with RSTS (24%) to have keloids. The 15 Dutch and 12 U.K. individuals with RSTS with keloids demonstrated that most patients have multiple keloids (n > 1: 82%; n > 5: 30%). Mean age of onset is 11·9 years. The majority of keloids are located on the shoulders and chest. The mean length × width of the largest keloid was 7·1 × 2·8 cm, and the mean thickness was 0·7 cm. All affected individuals complained of itching. Generally, treatment results were disappointing.

CONCLUSIONS

Keloids occur in 24% of individuals with RSTS, either spontaneously or after a minor trauma, usually starting in early puberty. Management schedules have disappointing results. RSTS is a Mendelian disorder with a known molecular basis, and offers excellent opportunities to study the pathogenesis of keloids in general and to search for possible treatments.

Plantar keloids: diagnostic and therapeutic issues in six patients

BACKGROUND

Keloids are benign fibro-proliferative skin lesions that very rarely occur on the soles. Because of their rarity, the diagnosis of plantar keloids can be difficult. We describe the clinical and histopathological characteristics of eight plantar keloids.

METHODS

All patients presenting with plantar keloids between 2005 and 2012 in our Dermatology unit were retrospectively included. Diagnosis was definitely established by re-reading of pathological slides in all cases. Clinical characteristics, histopathological features, treatments given and their results were collected.

RESULTS

Six patients were included. Five patients had a single plantar keloid and one had three lesions. They all were of African descent. Only one patient remembered of a previous injury at the site of the keloid. Three patients presented with associated extra-plantar keloids. In four patients, the diagnosis of keloid was not initially suspected clinically or histologically. Re-reading of the clinical photographs showed that the eight plantar keloids shared common morphological features, leading to a distinctive clinical picture, defined by a hardened lesion of rounded or polycyclic shape, with a pink surface crossed by keratotic furrows and the presence of a hyperkeratotic rim. Concerning pathological features, typical hyalinized collagen can be missing and deep fibrosis should not rule out the diagnosis of keloid. Intralesional injection of triamcinolone acetonide and orthopaedic shoes were useful. All patients who had surgical excision presented recurrence.

CONCLUSION

The knowledge of the clinical features of plantar keloids is helpful to the diagnosis. There is no well-established treatment, but supportive measures are important.

Follicular and scarring disorders in skin of color: presentation and management

Skin of color, also known as ethnic skin, is described as skin of individuals of African, Asian, Hispanic, Native-American, Middle Eastern, and Pacific Island backgrounds. Differences in hair morphology, hair grooming, cultural practices, and susceptibility to keloid scarring exist within these populations and have been implicated in hair, scalp, and skin disorders. Acne keloidalis (AK), central centrifugal cicatricial alopecia (CCCA), dissecting cellulitis of the scalp (DCS), pseudofolliculitis barbae (PFB), traction alopecia (TA), and keloids are the most prevalent follicular and scarring disorders in skin of color. They have been associated with disfigurement, permanent hair loss, emotional distress, and decreased quality of life. Hair grooming practices, such as the use of chemical relaxers, heat straightening, and tight braiding and weaving can cause scalp irritation and follicular damage and are linked to the pathogenesis of some of these conditions. Consequently, patient education and behavior modifications are integral to the prevention and management of these disorders. Scarring disorders are also of concern in ethnic populations. Keloid scarring is more prevalent in individuals of African, Asian, and Hispanic descent. The scarring alopecia CCCA is almost exclusively seen in patients of African descent. Therapeutic regimens such as intralesional corticosteroids, surgical excision, and laser therapy can be effective for these follicular and scarring disorders, but carry a risk of dyspigmentation and keloid scarring. Ethnic skin and hair may present unique challenges to the clinician, and knowledge of these differences is essential to providing quality care.

[Keloid scars of the head and neck]

A keloid scar is a benign proliferative lesion of dermic collagen. It is predominant in black skin patients. It is most commonly located on the head and neck. Skin trauma and a genetic predisposition may be responsible for the keloid scar. Nevertheless, the pathogenesis of keloid scar is still unclear, and no currently available treatment is 100% effective. The authors had for aim to review the current data on keloid scar pathogenesis and treatment for an optimal management of this condition.

Therapeutic hotline: An alternative adjuvant treatment after ear keloid excision using a custom-made methyl methacrylate stent

The efficacy of most pressure devices developed for treatment of ear keloids is limited by the insufficient control of the applied pressure, sometimes causing pain and repeated bleeding with a subsequently increased risk of infections and cosmetic problems. The present study aims to describe the efficacy of the custom-made methyl methacrylate stent in patients that were surgically treated for ear keloids and afterward underwent pressure therapy. The recurrence rate of the ear keloids was evaluated after at least 12 months. Adjuvant treatment with the methyl methacrylate stent resulted in an 83% success rate in our experience with 23 patients that completed the intended therapeutic duration of 18 months. No cases of severe complications were seen during or after the treatment. Furthermore, all the items of the Patient and Observer Scar Assessment Scale resulted in a statistically significant improvement of the scar (p < 0.05). Postoperative pressure therapy with the custom-made methyl methacrylate stent seems efficacious, safe, and is usable for keloids of both the helix and the earlobe.