Practice development


Innovations


Treatment innovations in hypertrophic and keloid scars


Authors: Zee Upton, Emily Lynam


This article examines the latest innovations and research in the diagnosis and treatment of hypertrophic and keloid scars. It looks at the latest evidence for targeting molecular and cellular pathways as well as emphasising that speed of treatment is crucial in preventing scarring. The authors also outline the direction of future research into scarring and make some recommendations for practice.


INTRODUCTION Hypertrophic and keloid scars are defined as benign hyperproliferative growths that occur as an abnormal response to wound healing[1]


Page points


1. Hypertrophic and keloid scars are benign hyperproliferative growths


2. They occur as an abnormal response to wound healing


3. Treatments for abnormal scarring


now focus on targeting the molecular and cellular pathways involved


. .


As current aesthetic surgical techniques become more standardised and the results more predictable, there is a fine line between acceptable and unacceptable outcomes[2]


Consequently, current management of hypertrophic and keloid scars include a wide range of techniques, from traditional invasive methods to intra-lesional and topical application of agents designed to take effect on a cellular level[3]


. References


1. Robles, DT, Berg D. Abnormal wound healing: keloids. Clin Dermatol 2007; 25(1): 26–32.


2. Widgerow AD, Chait LA, Stals R, Stals PJ. New innovations in scar management. Aesthetic Plast Surg, 2000; 24(3): 227–34.


3. Reish RG, Eriksson E. Scars: a


review of emerging and currently available therapies. Plast Reconstr Surg 2008; 122(4): 1068–78


4. Bush J, So K, Mason T, Occleston NL, O’Kane S, Ferguson MW.


Therapies with emerging evidence of efficacy: avotermin for the


improvement of scarring. Dermatol Res Pract, 2010; pii: 690613.


RESEARCH DEVELOPMENTS It is evident in the literature that treatments for abnormal scarring have turned towards targeting the molecular and cellular pathways involved. Differences in wound healing and scar outcome between early foetal and adult wounds led to interest in the role of the transforming growth factor beta (TGF-β) family of cytokines in scar formation[4]


. It is


known that TGF-β isoforms 1 and 2 participate in increasing collagen synthesis, while isoform 3 is involved in scar prevention[5]


. TGF-β3 is


predominantly induced in the later stages of wound healing and has been found to reduce connective tissue deposition[6]


. Moreover, the


treatment of cutaneous rat wounds with TGF- β3 was demonstrated to reduce scarring by Shah et al in 1995[7]


. Extensive pre-clinical and human


phase I and II clinical trial programmes investigating the use of human recombinant TGFβ3, avotermin (Juvista®


, Renovo) have


confirmed its scar improving efficacy, resulting in macroscopic and histological improvements in scar architecture, with


7 Wounds International Vol 2 | Issue 1 | ©Wounds International 2011


Landmark study One of the most significant studies from the authors’ perspective was performed by Deitch et al in 1983[13]


the factors associated with an increased risk of hypertrophic burn scar development.


improved restitution of the epidermis and an organisation of dermal extracellular matrix that more closely resembles normal skin. Avotermin has been shown to be well tolerated and is currently undergoing phase III clinical development[4]


. In contrast to the development of


avotermin for preventing scar development, silicone gel sheets (SGS) are another treatment that have been used as a topical treatment for abnormal scars since 1983[8]


. Despite their beneficial effect on


hypertrophic and keloid scars, however, the mechanism behind their use is still unknown. The authors’ laboratory has investigated the mechanism of SGS action on hypertrophic scarring and has found that low molecular weight silicone species, applied to fibroblasts derived from hypertrophic scars, have the ability to induce apoptosis[9]


.


RESEARCH Clinical similarities are clearly evident between hypertrophic and keloid scars but some clinical, histological and epidemiological differences are present, suggesting that they may be distinct from one another[10-12]


. However, most


methods for treating abnormal scars are used for both hypertrophic and keloid scars. Clinical differentiation between hypertrophic and keloid scars is required before the initiation of any treatment, particularly surgical or laser- related manipulations[11]


.


. This study involved investigating


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