Open access peer-reviewed chapter

Hypertrophic Scarring

Written By

Jesus Escriva-Machado, Eduardo Camacho-Quintero, Alejandro Maciel-Miranda, Samuel Almeida-Navarro and Julia De la Luz-Hernandez

Submitted: 20 June 2019 Reviewed: 06 December 2019 Published: 29 April 2020

DOI: 10.5772/intechopen.90792

From the Edited Volume

Wound Healing

Edited by Muhammad Ahmad

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Abstract

Hypertrophic scars represent important problems because of the presence of pain, pruritus, contractures, as well as unsatisfactory aesthetic results. Currently, the evidence shows that a multidisciplinary management through prevention, adequate choice of suture, atraumatic surgical technique, and early noninvasive measures can favor the handling of these problems and continue with invasive measures that employ intralesional drugs. Clearly, the combination of surgical, technical, and pharmacological interventions will maximize therapeutic results.

Keywords

  • hypertrophic scar
  • scar
  • pathological scar
  • surgical scar

1. Introduction

Hypertrophic scars (HS) are defined as a pathological scars that have abnormal thickness and are raised from the previous wound [1]. Such scars are the most common complication of burn injury and abnormal wound healing response after traumatic injury, surgery, or inflammation [2, 3]. These lesions are characterized by their red to purple color, raised appearance, decreased pliability, and tenderness with concomitant symptoms including pruritus and pain [4, 5, 6, 7, 8, 9]. Patients with HS may suffer from stiffness, cosmetic disfigurement, joint contractures, as well as impediment in physical function and daily activities, and even psychological issues such as depression or anxiety [1, 10, 11, 12].

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2. Epidemiology

The best clinical predictor for the development of hypertrophic burn scars is a prolonged inflammatory wound healing phase. This result usually corresponds with a wound that has not epithelialized and continues to exudate for more than 3 weeks [13]. Hypertrophic scars generally develop at about 2 months after a burn and will continue to proliferate for a year or longer. HS maturation may not occur until 18 or even 24 months after a burn. The exact time point of regression or maturation of HS remains unknown [8, 9, 10, 14, 15].

According to the literature, about 32–72% of surgical skin wounds result in HS after 1 year [16, 17]. In Asian, the prevalence rate of HS after burn injury is as high as 70%, much higher than in Caucasian populations. Contractures after burns have a prevalence of 38–54% of patients, with up to 46% patients undergoing at least one reconstructive procedure after their acute hospital stays [18, 19] (Figure 1).

Figure 1.

Patient with a history of flame burn. Hypertrophic scars that affect the first interdigital space.

In order to prevent and treat pathologic wounds, one must first understand the basics of normal wound healing.

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3. Wound healing

The desirable result of normal wound healing is replacement of the initial hemostatic clot with skin that approximates the aesthetic, mechanical, and functional properties of the preinjury tissue.

Historically, wound healing has been arbitrarily divided into three phases, with some authors adding hemostasis as the inciting phase. Although wound healing occurs on a time continuum, division of the process into phases allows for ease of description and evaluation. Changes in the steps of normal wound healing may result in either a “hypoplastic” or chronic nonhealing wound or a hypertrophic “over-healed” wound [20].

The clotting cascade is activated immediately after trauma, a consequence of the disruption of the vascular endothelium and exposure of the basal lamina that results in extravasation of blood constituents and concurrent platelet activation. Subsequently, the release of growth factors causes the deposition of extracellular matrix (transforming growth factor β), chemotaxis (platelet-derived growth factor), epithelialization (fibroblast growth factor and epidermal growth factor), and angiogenesis (vascular endothelial growth factor) [21, 22].

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4. Inflammatory

An inflammatory phase develops and persists for 4–6 days. This phase is characterized by hemostasis and leukocytic infiltration led by polymorphonuclear leukocytes. Neutrophils, as well as monocytes, fibroblasts, and endothelial cells deposit on a fibrin scaffold formed by platelet activation. The presence of neutrophils is followed closely by monocytes that are quickly activated into tissue macrophages. These cells cause further tissue debridement and secrete additional cytokines as well as growth factors that promote fibroblast proliferation, angiogenesis, and keratinocyte migration [23].

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5. Proliferative

The proliferative phase of wound healing begins at 4 days and persists up to 14 days; this phase is heralded by the transformation of monocytes to macrophages. Keratinocytes initiate epithelialization and are present on the wound edge as well as from dermal appendages such as hair follicles, sweat, and sebaceous glands. Epidermal growth factor, fibroblast growth factor, transforming growth factor β, and multiple cytokines originate cell detachment and mitotic division; then, fibroblasts appear in the wound after 24 hours of this stimulation and produce collagen. This process requires adequate oxygen supply. In fact, without oxygen to assist in the hydroxylation of proline and lysine residues, chemical bonds will not form appropriately to create a mature form of collagen. These bonds are very critical because their absence can prolong the stage and result in a chronic wound. They serve as the basis for the final stage of maturation and remodeling [24].

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6. Maturation

Appropriate wound maturation and remodeling result in a quickly healed and minimally visible scar; whereas, prolongation or deviations from this phase can cause hypertrophic, keloid scars or chronic nonhealing wounds. This initial collagen is thinner than uninjured. Type III collagen initially comprises 30% of the granulation tissue matrix, compared with 10–20% in uninjured skin. Over time, the ratio of type III collagen decreases, and type I collagen increases. An overall increase in collagen formation is seen for 4–5 weeks; after this time wound strength increases and parallels the increase in type I collagen [25, 26].

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7. Cellular basis, signals and pathways of hypertrophic scars

Fibroblasts and myofibroblasts are pivotal effectors cells in HS [27]. The activation of fibroblasts and differentiation into myofibroblasts (that are a phenotypically intermediate cell type between fibroblasts and smooth muscle cells) are the central processes in the pathophysiology of hypertrophic scars. The larger the area of the wound, the greater migration of myofibroblasts. This situation results in more prominent scarring [28, 29]. Many origins of fibroblasts or myofibroblasts have been characterized: local dermis and subcutaneous tissues around the wound site, pericytes and vascular smooth muscle cells, tubular epithelial cells through epithelial-mesenchymal transition (EMT), tissue specific stem cells, and bone marrow-derived peripheral blood fibrocytes (Figure 2) [30].

Figure 2.

Activation of fibroblasts and differentiation into myofibroblasts are the central processes in the pathophysiology of hypertrophic scars.

The proliferative fibroblasts produce massive collagen and make extracellular matrix (ECM) that accumulates below the dermis. One sign thought to be of particular importance is that transforming growth factor-beta (TGF-b), acting through a signaling pathway in fibroblasts, appears to cause an increase in production of ECM and leads to cellular proliferation [31, 32]. Over time, some cells can develop autocrine TGF-b positive feedback loops that can lead to a self-propagating cycle of excessive extracellular matrix production and cell proliferation. Moreover, fibroblasts infiltrate and degrade the fibrin clot by producing matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs). This action results in an imbalance between the formation and degradation of matrix [33].

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8. Risk factors

Risk factors for the development of pathologic scarring in the setting of burns have been reported to include darker skin color [1, 34], female sex [35], young age [17, 35, 36], allergy [16, 37], bacterial colonization [38], stretch and burns to the neck or upper limb [35], multiple surgical procedures [35], meshed skin graft [35], increased time to healing [1, 35, 38, 39], and burn depth [35].

Factors that reduce the risk of presenting HS are: chemotherapy [40], smoking [17], statins [41], and genetic background that does not have association [42] (Table 1).

Increase HS
Darker skin colorStretch
Female sexNeck and upper limb
Young ageMultiple surgical procedures
AllergyMeshed skin graft
Bacterial colonizationIncreased time healing
Burn depth
Decrease HS
Chemotherapy
Smoking
Statins

Table 1.

Overview of factors associated with the development and reduce risk of HS described by other authors to date.

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9. Genetic

No convincing evidence exists for a familial pattern in patients who suffer from HS. In a systematic review, the authors did not find any pedigree studies on HS [42, 43].

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10. Dark skin

In the literature, dark skin has a higher incidence of HS compared with lighter skin of Caucasians. Dark skin contains more and larger fibroblasts that deposit more collagen, related to what was previously written [1, 34, 36].

11. Female sex

Gangemi and colleagues observed in a multivariate regression model that female sex, young age, burn sites on the neck and/or upper limbs, multiple surgical procedures, and meshed skin grafts were risk factors for postburn pathologic scarring [35].

12. Age

Evidence supports the negative association of age with HS. Excessive scars develop mostly in younger patients between 11 and 30 years old. The inflammatory response decreases with age: epidermal turnover is slower in elderly individuals, and the epidermis contains fewer cells [17, 35, 36, 44].

13. Allergy

Hypothesize that increased degranulation of mast cells observed in allergic individuals supports HS formation. This relationship of allergy with HS formation is supported by level III evidence [16, 37].

14. Bacterial colonization

Bacterial toxins stimulate and prolong the inflammatory phase of wound healing and, thereby stimulate HS [38, 45].

15. Evaluation of hypertrophic scar

Currently no standardized system method exists to assess postsurgical scars. In the literature, scar assessment has mainly been focused on burn scars, but an increasing interest in postsurgical scars is seen, both to evaluate postoperatively as well as to have a closer and objective monitoring when therapeutic measures are applied so as to conclude whether the management is effective or, on the contrary worsening the situation of the scar [4, 9].

Comprehensive scar assessment must include three different dimensions: (a) physical characteristics; (b) cosmetic appearance; and (c) patient’s symptoms (Table 2).

Scar assessment
Physical characteristics
Cosmetic appearance
Symptoms

Table 2.

Points to scar assessment.

To date, only four scales have been psychometrically studied: the Vancouver Scar Scale (VSS), the Patient and Observer Scar Assessment Scale (POSAS), the Manchester Scar Scale (MSS), and the Stony Brook Scar Evaluation Scale (SBSES) (Table 3).

Scar scales
Vancouver scar scale
Patient and observer scar assessment scale
Manchester scar scale
Stony Brook scar evaluation scale

Table 3.

Scales psychometrically studied for the evaluation of scars.

16. Vancouver scar scale (VSS)

The VSS was created in 1990 and is the most widely used rating scale for scars. Four physical characteristics are scored: height, pliability, vascularity, and pigmentation. Each variable is ranked to obtain a total score ranging from 0 to 13, with 0 representing normal skin [46, 47] (Table 4).

Table 4.

Vancouver scar scale.

17. Manchester scar scale

The MSS includes six items: contour, texture, color, distortion, shiny surface, and overall patient’s opinion [47].

18. Patient and observer scar assessment scale

The POSAS is a recent and promising scar assessment tool that incorporates both observer and patient scar ratings [47, 48].

19. Stony Brook scar evaluation scale

Scars are assigned 0–1 point for the presence or absence of the following: width greater than 2 mm at any point of the scar, raised (or depressed) scar, and darker coloration than surrounding skin. The total score is then derived from the scale and ranges from 0 (worst) to 5 (best) [47, 49].

20. Treatment of hypertrophic scar

Different methods have been described for the treatment of hypertrophic scars. Among those have been found prevention, re-excision with primary closure, massages, compression clothes, silicone sheets, intralesional injections, laser therapy and topical treatments (Table 5).

Treatment of hypertrophic scar
No invasive
Prevention
Pressure garment therapy
Scar massage
Laser therapy
Silicone gel sheeting
Invasive
Triamcinolone acetonide
5-Fluorouracil

Table 5.

Treatment of hypertrophic scars.

21. Prevention

The prevention is the conjunction of measures that reduce inflammation and provide rapid wound closure such as early debridement of dead space, reducing the risk of infection through rinsing and disinfection, as well as optimal dressings that provide moist wound healing and/or early surgical wound coverage. During the operation, the surgeon should also use adequate sutures and avoid excessive tension. Surgical closure must be meticulous with an atraumatic technique to generate a successful and minimal linear scar. In the training of plastic surgery, the use of fine and atraumatic instruments is taught for the handling of the tissues for example hooks for retraction. Without a doubt, the tension found in the closure of a wound plays a very important role in widened and hypertrophic scars; these tension forces separate the edges of the wound and generate a wider scar with time. This result can be decreased with the liberation and advancement of the edges, in addition to the placement of correct subdermal sutures [50].

Once the wound has been prepared and is ready for closure, the proper suture and suture technique must be selected. Wounds may be closed with simple interrupted, horizontal mattress, vertical mattress, figure-of-eight, or running sutures. The choice of the suture is of great importance, and most of the time despised, attention should be paid to the estimated time to resorption since the suture may or may not provide adequate support during the healing process. With a Level II of Therapeutic Evidence, polydioxanone (PDS) has been found to result in less scar widening and less scar hypertrophy at 6 months compared with polyglycolic acid (PGA). In the first 3 weeks of wound healing, the strength of a wound is only a small fraction of its eventual strength. Sutures removed or degraded before this time have little effect in preventing wound spreading. Polyglactic acid suture loses strength after 3 weeks, at which time the wound is still relatively weak. These results are similar to removing a nylon suture from the wound in 1 week [51, 52].

Leaving a permanent intradermal suture in place for several months has been shown to decrease spreading, and a synthetic suture possibly retains strength for 6–8 weeks and may have the same effect. This result is caused by the difference in the absorption time and what comes from the loss of tensile strength. On an average PGA scars were wider than PDS scars by 33% (means 9.6, 7.2), the difference that was statistically highly significant (Wilcoxon test p < 0.001) [51, 52].

In another study that used the Vancouver Scar Scale (VSS), the scar’s width and quality of polydioxanone (PDS) was compared with that of polyglactin 910. The scars were evaluated at 1, 3 and 4 months postoperatively. On follow-up, the mean scar width in Polyglactin 910 was significantly more than that of PDS. The VSS score was significantly lower in the PDS group at the third and fourth month follow up and signified better scar quality [53].

22. Noninvasive measures

22.1 Pressure garment therapy (PGT)

The theory behind the use of PGT may be quite simple and relies on two main concepts; first, the restriction of blood flow to the scar area inhibits the growth of hypertrophic scar tissue and second constant compression does too [54]. Some evidence indicates that PGT may have an effect on the remodeling of hypertrophic burn scar elements such as fibrillin and elastin [55]. In an experimental model with swine that received pressure treatment with a device mounting and delivery at 30 mm Hg of constant pressure for 2 weeks, the total collagen quantification using hydroxyproline assay showed a 51.9% decrease after pressure initiation. Pressure treated scars also had lower levels of collagen I and III after pressure treatment (P < 0.05) compared with sham and untreated scars [56]. Using a newly developed pressure therapy system, the Smart Pressure Monitored Suits. Pre and post treatment comparison demonstrated significant improvement in scar pigmentation, thickness, VSS scores, as well as scores of pain and itch (p < 0.01) for the early intervention group prescribed within 60 days after injuries compared with the late intervention group prescribed after 61 days. The early group demonstrated superior effect in improving scar lightness, yellowness (p < 0.01), thickness (p < 0.01), pigmentation score (p < 0.05) and pain score (p < 0.01) than the late group in comparison between the two groups at similar postburn timing [57].

However, a meta-analysis of clinical results suggests that PGT does not appear to alter global scar scores, but does appear to improve scar height, although this difference is small and of questionable clinical importance. The beneficial effects of PGT remain unproven while the potential morbidity and cost are not insignificant [58].

22.2 Scar massage

Scar massage is used in burn units globally to improve functional and cosmetic outcomes of hypertrophic scarring following a burn; however, the evidence to support this therapy is unknown [59].

22.3 Laser therapy

The three main groups of lasers that can be used to improve scars include pulsed dye lasers (PDLs), Nd:YAG lasers, as well as ablative and nonablative fractional lasers.

A systematic review of the effectiveness of the ablative 10,600 nm CO2 laser, shows objective improvement in scar color, thickness, and sensation, but not in scar elasticity. All studies reported improvements in the mean total VSS score and/or VSS component scores (pliability, height, vascularity, pigmentation), without statistically significant differences between raters. Statistically significant improvements in both the patient and the observer sections of the POSAS were reported after CO2 laser treatment. Despite these positive findings, all studies were of low or unclear quality. As a result, insufficient scientific evidence exists to determine the effectiveness of laser therapy for hypertrophic burn scars from this systematic review [60].

22.4 Silicone gel sheeting (SGS)

In 2006, a Cochrane review found weak evidence to support the use of SGS [61]. SGC was effective to reduce thickness, pain, itchiness, and pliability of hypertrophic scars in Chinese the population after 6 month’s intervention [62]. Silicone products, either in gel or sheet, are superior to onion extracts including heparin and allantoin in the treatment of the hypertrophic scar [63].

23. Invasive treatment

23.1 Intralesional corticosteroids

In patients with ongoing hypertrophy, more invasive measures are indicated. Intralesional corticosteroids is the only invasive option that has enough supporting evidence [64, 65]. The most commonly used is triamcinolone acetonide (TAC), the dose and treatment interval is variable ranging from 10 to 40 mg/ml given between 2 and 4 weeks interval. The success rate is 50–100% in different studies with 9–50% experiencing recurrence [66, 67]. The TAC injection should be limited to the scar and avoid the periscar tissues. The adverse outcomes of skin atrophy, pigmentation, and telangiectasias are unacceptable by some patients [68, 69, 70, 71].

The injection of TAC is not contraindicated in children, but that dose adaption to the child’s weight is advised to avoid systemic exposure [72, 73].

Additional injectable treatment options that may help to treat hypertrophic scars (and keloids) include 5-fluorouracil and verapamil.

23.2 5-Fluorouracil (5FU)

The use of antineoplastic agents as treatment options is logical because these abnormal tissues are in hypermetabolic states. 5-FU has been known to affect the fibroblast proliferation in tissue cultures because of its antimetabolite activity and has been shown to be an effective treatment for inflamed hypertrophic scars [28].

23.3 Triamcinolone acetonide and 5FU

This combination is associated with significantly greater reductions in scar size and erythema compared with triamcinolone acetonide alone in a 12-week double-blind study of 40 patients [74]. In a randomized control trial that include 120, patients the mean reduction in scar height was significant in 5FU + TAC group versus TAC alone. Recurrence was seen in 39.2% of patients of the TAC group while in 17.5% of 5FU + TAC group (P = 0.012) [75].

Verapamil is a calcium channel antagonist that both decreases collagen synthesis and increases collagen breakdown. In a randomized, single-blind study of 54 patients with hypertrophic scars or keloids, scar vascularity, pliability, height, and width were reduced with intralesional verapamil, although the rate of reduction in these parameters was slower than with intralesional triamcinolone [76]. A randomized controlled of 50 patients the VSS scores were achieved with no therapeutic event or significant improvement was seen in verapamil group versus TAC group [77].

Pruritus is a chronic problem associated with many hypertrophic scars. Besides the emollient creams mentioned above, the use of local or systemic antihistamines may be useful and depends on the total body surface area involved in the areas of itchiness. Some early evidence suggests that naltrexone may be a useful treatment for burn-related itching [78].

23.4 Surgical treatment

Surgical interventions for burn scars are usually postponed until the scar is considered “mature” or what may be 6–12 months after maturity, primarily because of the concern of recurrence of the scar. This may also have been influenced by burn scar reconstructive release surgeries performed by grafting and flaps. Most believe that the best option is the treatment with flaps [79] (Figures 3 and 4).

Figure 3.

Release of first interdigital space with flap based on perforating of digital artery of index finger.

Figure 4.

Multiple syndactyly release in a single time with seagull wings flap.

References

  1. 1. Bombaro KM, Engrav LH, Carrougher GJ, et al. What is the prevalence of hypertrophic scarring following burns? Burns. 2003;29(4):299-302
  2. 2. Aarabi S, Longaker MT, Gurtner GC. Hypertrophic scar formation following burns and trauma: New approaches to treatment. PLoS Medicine. 2007;4:1464-1470
  3. 3. Wolfram D, Tzankov A, Pülzl P, Piza-Katzer H. Hypertrophic scars and keloids—A review of their pathophysiology, risk factors, and therapeutic management. Dermatologic Surgery. 2009;35:171
  4. 4. Bell L, McAdams T, Morgan R, et al. Pruritus in burns: A descriptive study. The Journal of Burn Care & Rehabilitation. 1988;9:305
  5. 5. Slemp AE, Kirschner RE. Keloids and scars: A review of keloids and scars, their pathogenesis, risk factors, and management. Current Opinion in Pediatrics. 2006;18:396
  6. 6. Anthonissen M, Daly D, Janssens T, Van den Kerckhove E. The effects of conservative treatments on burn scars: A systematic review. Burns. 2016;42(3):508-518
  7. 7. Rabello FB, Souza CD, Farina Júnior JA. Update on hypertrophic scar treatment. Clinics (São Paulo, Brazil). 2014;69(8):565-573
  8. 8. Nedelec B, Correa JA, de Oliveira A, LaSalle L, Perrault I. Longitudinal burn scar quantification. Burns. 2014;40(8):1504-1512
  9. 9. Van den Kerckhove E, Stappaerts K, Fieuws S, Laperre J, Massage P, Flour M, et al. The assessment of erythema and thickness on burn related scars during pressure garment therapy as a preventive measure for hypertrophic scarring. Burns. 2005;31(6):696-702
  10. 10. Bock O, Schmid-Ott G, Malewski P, Mrowietz U. Quality of life of patients with keloid and hypertrophic scarring. Archives of Dermatological Research. 2006;297(10):433-438
  11. 11. Robert R, Meyer W, Bishop S, Rosenberg L, Murphy L, Blakeney P. Disfiguring burn scars and adolescent self-esteem. Burns. 1999;25:581
  12. 12. Taal L, Faber AW. Posttraumatic stress and maladjustment among adult burn survivors 1 to 2 years postburn. Part II: The interview data. Burns. 1998;24:399
  13. 13. Matsumura H, Engrav LH, Gibran NS, et al. Cones of skin occur where hypertrophic scar occurs. Wound Repair and Regeneration. 2001;9(4):269-277
  14. 14. Ensen LLM, Parshley PFM. Postburn scar contractures: Histology and effects of pressure treatment. Journal of Burn Care & Research. 1984;5(2):119-123
  15. 15. Oliveira GV, Chinkes D, Mitchell C, Oliveras G, Hawkins HK, Herndon DN. Objective assessment of burn scar vascularity, erythema, pliability, thickness, and planimetry. Dermatologic Surgery. 2006;31(1):48-58
  16. 16. Niessen FB, Schalkwijk J, Vos H, Timens W. Hypertrophic scar formation is associated with an increased number of epidermal Langerhans cells. The Journal of Pathology. 2004;202:121e9
  17. 17. Mahdavian Delavary B, van der Veer WM, Ferreira JA, Niessen FB. Formation of hypertrophic scars: Evolution and susceptibility. Journal of Plastic Surgery and Hand Surgery. 2012;46:95e101
  18. 18. Chen J, Li-Tsang CWP, Yan H, Liang G, Tan J, Yang S, et al. A survey on the current status of burn rehabilitation services in China. Burns. 2013;39(2):269-278
  19. 19. Li-Tsang CWP, Lau JCM, Chan CCH. Prevalence of hypertrophic scar formation and its characteristics among the Chinese population. Burns. 2005;31(5):610-616
  20. 20. Gabriel V. Hyperthrophic scar. Physical Medicine and Rehabilitation Clinics of North America. 2011;22:301-310
  21. 21. Janis J, Harrison B. Wound healing: Part I. Basic science. Plastic and Reconstructive Surgery. 2016;138:9S
  22. 22. Barrientos S, Stojadinovic O, Golinko MS, Brem H, Tomic-Canic M. Growth factors and cytokines in wound healing. Wound Repair and Regeneration. 2008;16:585-601
  23. 23. Witte MB, Barbul A. General principles of wound healing. The Surgical Clinics of North America. 1997;77:509-528
  24. 24. Kivisaari J, Vihersaari T, Renvall S, Niinikoski J. Energy metabolism of experimental wounds at various oxygen environments. Annals of Surgery. 1975;181:823-828
  25. 25. Broughton G 2nd, Janis JE, Attinger CE. Wound healing: An overview. Plastic and Reconstructive Surgery. 2006;117(7 Suppl):1e-1S
  26. 26. Ehrlich HP, Krummel TM. Regulation of wound healing from a connective tissue perspective. Wound Repair and Regeneration. 1996;4:203-210
  27. 27. Chun Q , Zhiyong W, Fei S, Xiqiao W. Dynamic biological changes in fibroblasts during hypertrophic scar formation and regression. International Wound Journal. 2014
  28. 28. Sarrazy V, Billet F, Micallef L, Coulomb B, Desmouliere A. Mechanisms of pathological scarring: Role of myofibroblasts and current developments. Wound Repair and Regeneration. 2011;19(Suppl 1):s10-s15
  29. 29. Curran TA, Ghahary A. Evidence of a role for fibrocyte and keratinocyte-like cells in the formation of hypertrophic scars. Journal of Burn Care & Research. 2013;34:227-231
  30. 30. Lian N, Li T. Growth factor pathways in hypertrophic scars: Molecular pathogenesis and therapeutic implications. Biomedicine and Pharmacotherapy. 2016;84:42-50
  31. 31. Armour A, Scott PG, Tredget EE. Cellular and molecular pathology of HTS: Basis for treatment. Wound Repair and Regeneration. 2007;15:S6-S17
  32. 32. Gabriel V. Transforming growth factor-beta and angiotensin in fibrosis and burn injuries. Journal of Burn Care & Research. 2009;30(3):471-481
  33. 33. Ulrich D, Ulrich F, Unglaub F, Piatkowski A, Pallua N. Matrix metalloproteinases and tissue inhibitors of metalloproteinases in patients with different types of scars and keloids. Journal of Plastic, Reconstructive & Aesthetic Surgery. 2010;63:1015-1021
  34. 34. Deitch EA, Wheelahan TM, Rose MP, Clothier J, Cotter J. Hypertrophic burn scars: Analysis of variables. Journal of Trauma and Acute Care Surgery. 1983;23:895-898
  35. 35. Gangemi EN, Gregori D, Berchialla P, et al. Epidemiology and risk factors for pathologic scarring after burn wounds. Archives of Facial Plastic Surgery. 2008;10:93-102
  36. 36. Ketchum LD, Cohen IK, Masters FW. Hypertrophic scars and keloids: A collective review. Plastic and Reconstructive Surgery. 1974;53:140e54
  37. 37. Smith CJ, Smith JC, Finn MC. The possible role of mast cells (allergy) in the production of keloid and hypertrophic scarring. The Journal of Burn Care & Rehabilitation. 1987;8:126e31
  38. 38. Baker RH, Townley WA, McKeon S, Linge C, Vijh V. Retrospective study of the association between hypertrophic burn scarring and bacterial colonization. Journal of Burn Care & Research. 2007;28:152e6
  39. 39. Cubison TC, Pape SA, Parkhouse N. Evidence for the link between healing time and the development of hypertrophic scars (HTS) in paediatric burns due to scald injury. Burns. 2006;32:992-999
  40. 40. Lee TJ, Jeong WS, Eom JS, Kim EK. Adjuvant chemotherapy reduces the incidence of abdominal hypertrophic scarring following immediate TRAM breast reconstruction. Breast Cancer Research and Treatment. 2013;137:767e71
  41. 41. Ko JH, Kim PS, Zhao Y, Hong SJ, Mustoe TA. HMG-CoA reductase inhibitors (statins) reduce hypertrophic scar formation in rabbit ear wounding model. Plastic and Reconstructive Surgery. 2012;129:252ee61e
  42. 42. Bayat A, Bock O, Mrowietz U, Ollier WE, Ferguson MW. Genetic susceptibility to keloid disease and hypertrophic scarring: Transforming growth factor beta 1 common polymorphisms and plasma levels. Plastic and Reconstructive Surgery. 2003;111:535e43
  43. 43. Brown JJ, Bayat A. Genetic susceptibility to raised dermal scarring. The British Journal of Dermatology. 2009;161:8e18
  44. 44. Enoch S, Price PE. Cellular, molecular and biochemical differences in the pathophysiology of healing between acute wounds, chronic wounds and wounds in the aged. World Wide Wounds. 2004. Available from: http://www.worldwidewounds.com
  45. 45. Edwards R, Harding KG. Bacteria and wound healing. Current Opinion in Infectious Diseases. 2004;17:91e6
  46. 46. Sullivan T, Smith J, Kermode J, Mclver E, Courtemanche DJ. Rating the burn scar. The Journal of Burn Care & Rehabilitation. 1990;11:256-260
  47. 47. Vercelli S, Ferriero G, Sartorio F, Stissi V, Franchignoni F. How to assess postsurgical scars: A review of outcome measures. Disability and Rehabilitation. 2009;31(25):2055-2063
  48. 48. Van de Kar AL, Corion LUM, Smeulders MJC, Draaijers LJ, van der Horst CM, van Zuijlen PP. Reliable and feasible evaluation of linear scars by the patient and observer scar assessment scale. Plastic and Reconstructive Surgery. 2005;116:514-522
  49. 49. Singer AJ, Arora B, Dagum A, Valentine S, Hollander JE. Development and validation of a novel scar evaluation scale. Plastic and Reconstructive Surgery. 2007;120:1892-1897
  50. 50. Bloemen MC, van der Veer WM, Ulrich MM, van Zuijlen PP, Niessen FB, Middelkoop E. Prevention and curative management of hypertrophic scar formation. Burns. 2009;35:463e75
  51. 51. Chantarasak ND, Milner RH. A comparison of scar quality in wounds closed under tension with PGA (Dexon) and polydioxanone (PDS). British Journal of Plastic Surgery. 1989;42:687-691
  52. 52. Weinzweig J. Chapter 1: Plastic Surgery Secrets. Second ed. Mosby: Elsevier; 2010. p. 5
  53. 53. Gupta D, Sharma U, Chauhan S, Anand Sahu S. Improved outcomes of scar revision with the use of polydioxanone suture in comparison to polyglactin 910: A randomized controlled trial. Journal of Plastic, Reconstructive & Aesthetic Surgery. 2018;71:1159-1163
  54. 54. Yildiz N. A novel technique to determine pressure in pressure garments for hypertrophic burn scars and comfort properties. Burns. 2007;33:59-64
  55. 55. Costa AM, Peyrol S, Porto LC, et al. Mechanical forces induce scar remodeling. Study in non-pressure-treated versus pressure-treated hypertrophic scars. The American Journal of Pathology. 1999;155(5):1671-1679
  56. 56. Tejiram S, Zhang J, Travis T, Carney B, Alkhalil A, Moffatt L, et al. Compression therapy affects collagen type balance in hypertrophic scar. Journal of Surgical Research. 2016;201:299e305
  57. 57. Li P, Wai Ping Li-Tsang C, Deng X, Wang X, Wang H, Zhang Y, et al. The recovery of post-burn hypertrophic scar in a monitored pressure therapy intervention programme and the timing of intervention. Burns. 2018;44:1451-1467
  58. 58. Anzarut A, Olson J, Singh P, et al. The effectiveness of pressure garment therapy for the prevention of abnormal scarring after burn injury: A meta-analysis. Journal of Plastic, Reconstructive & Aesthetic Surgery. 2009;62:77-84
  59. 59. Ault P, Plaza A, Paratz J. Scar massage for hypertrophic burns scarring—A systematic review. Burns. 2018;44:24-38
  60. 60. Zuccaro J, Ziolkowski N, Fish J. A systematic review of the effectiveness of laser therapy for hypertrophic burn scars. Clinics in Plastic Surgery. 2017;44:767-779
  61. 61. O’Brien L, Jones D. Silicone gel sheeting for preventing and treating hypertrophic and keloid scars (review). Cochrane Database of Systematic Reviews. 2006;1:CD003826
  62. 62. Li-Tsang C, Lau J, Choi J, Chan C, Jianan L. A prospective randomized clinical trial to investigate the effect of silicone gel sheeting (Cica-Care) on post-traumatic hypertrophic scar among the Chinese population. Burns. 2006;32:678-683
  63. 63. Karagoz H, Yuksel F, Ulkur E, Evinc R. Comparison of efficacy of silicone gel, silicone gel sheeting, and topical onion extract including heparin and allantoin for the treatment of postburn hypertrophic scars. Burns. 2009;35:1097-1103
  64. 64. Middelkoop E, Monstrey S, Teot L, Vranckx JJ, editors. Scar Management Practical Guidelines. Maca-Cloetens; 2011. p. 1e109
  65. 65. Mustoe TA, Cooter RD, Gold MH, et al. International clinical recommendations on scar management. Plastic and Reconstructive Surgery. 2002;110:560e71
  66. 66. Niessen FB, Spauwen PH, Schalkwijk J, Kon M. On the nature of hypertrophic scars and keloids: A review. Plastic and Reconstructive Surgery. 1999;104:1435e58
  67. 67. Nanda S, Reddy BS. Intralesional 5-fluorouracil as a treatment modality of keloids. Dermatologic Surgery. 2004;30:54-56
  68. 68. Al-Attar A, Mess S, Thomassen JM, Kauffman CL, Davison SP. Keloid pathogenesis and treatment. Plastic and Reconstructive Surgery. 2006;117:286e300
  69. 69. Ketchum LD, Smith J, Robinson D, Masters FW. The treatment of hypertrophic scar, keloid and scar contracture by triamcinoloneacetonide. Plastic and Reconstructive Surgery. 1966;38(3):209-218
  70. 70. Friedman SJ, Butler DR, Dittelkov MR. Perilesional linear atrophy and hypopigmentation after intralesional corticosteroid therapy. Journal of the American Academy of Dermatology. 1988;19:537-541
  71. 71. Juckett G, Hartman-Adams H. Management of keloids and hypertrophic scars. American Family Physician. 2009;80:253e60
  72. 72. Sclafani AP, Gordon L, Chadha M, Romo T III. Prevention of earlobe keloid recurrence with postoperative corticosteroid injections versus radiation therapy: A randomized, prospective study and review of the literature. Dermatologic Surgery. 1996;22:569e74
  73. 73. Patel PA, Bailey JK, Yakuboff KP. Treatment outcomes for keloid scar management in the pediatric burn population. Burns. 2012;38:767e71
  74. 74. Darougheh A, Asilian A, Shariati F. Intralesional triamcinolone alone or in combination with 5-fluorouracil for the treatment of keloid and hypertrophic scars. Clinical and Experimental Dermatology. 2009;34:219e23
  75. 75. Khalid F, Mehrose M, Saleem M, Yousaf M, Mujahid A, Rehman S, et al. Comparison of efficacy and safety of intralesional triamcinolone and combination of triamcinolone with 5-fluorouracil in the treatment of keloids and hypertrophic scars: Randomised control trial. Burns. 2019;45:69-75
  76. 76. Margaret Shanthi FX, Ernest K, Dhanraj P. Comparison of intralesional verapamil with intralesional triamcinolone in the treatment of hypertrophic scars and keloids. Indian Journal of Dermatology, Venereology and Leprology. 2008;74:343e8
  77. 77. Abedini R, Sasani P, Mahmoudi H, Nasimi M, Teymourpour A, Shadlou Z. Comparison of intralesional verapamil versus intralesional corticosteroids in treatment of keloids and hypertrophic scars: A randomized controlled trial. Burns. 2018;44:1482-1488
  78. 78. Jung SI, Seo CH, Jang K, et al. Efficacy of naltrexone in the treatment of chronic refractory itching in burn patients: Preliminary report of an open trial. Journal of Burn Care & Research. 2009;30(2):257-260. [discussion: 61]
  79. 79. Hudson DA, Renshaw A. An algorithm for the release of burn contractures of the extremities. Burns. 2006;32(6):663-668

Written By

Jesus Escriva-Machado, Eduardo Camacho-Quintero, Alejandro Maciel-Miranda, Samuel Almeida-Navarro and Julia De la Luz-Hernandez

Submitted: 20 June 2019 Reviewed: 06 December 2019 Published: 29 April 2020