The role of the epidermis and the mechanism of action of occlusive dressings in scarring

Abstract

The problem of cutaneous scarring has conventionally been approached as a pathology of the dermis. Multiple lines of evidence from the clinic, in vitro experiments, and in vivo animal and human studies, however, increasingly suggest that the epidermis plays a major role in the control of underlying dermal scar. Building on the demonstrated efficacy of silicone gel occlusion, in this paper we review the evidence for epidermal regulation of scar, and propose the novel hypothesis that dermal fibrosis is exquisitely linked to the inflammatory state of the epidermis, which in turn is linked to hydration state as a function of epidermal barrier function. In the spectrum of factors contributing to dermal scar, the epidermis and its downstream effectors offer promising new targets for the development of anti-scar therapies.

Wound bed preparation: A novel approach using HydroTherapy

“…HydroTac provides a continuum of hydration that aids wound healing.  Faster wound healing (Winter, 1962;Dyson et al, 1988;Beam et al, 2008)  Promote epithelialisation rate (Winter, 1962;Eaglstein, 2001;Ågren et al, 2001;Varghese et al, 1986;Rubio, 1991;Madden et al, 1989;Wigger-Alberti et al, 2009)  Promote dermal/wound bed healing responses, e.g., cell proliferation, ECM synthesis (Svensjö et al, 2000;Dyson et al, 1992;Mosti, 2013;Korting et al, 2010;Chen et al, 1992;Leung et al, 2010;Field & Kerstein, 1994;Dowsett & Ayello, 2004;Katz et al, 1991)  ReducI can't es scarring (Atiyeh et al, 2003(Atiyeh et al, ,2004O'Shaughnessy et al, 2009;Mustoe & Gurjala, 2011;Tandara et al, 2007;Hoeksema et al, 2013)  Retention of growth factors at wound site (Svensjö et al, 2000;Hackl et al, 2014;Powers et al, 2013;Chen et al, 1992;Attinger et al, 2006;Vogt et al, 1995)  Lower wound infection rates (Kannon & Garret, 1995;Hutchinson & Lawrence, 1991;Lawrence, 1994)  Reduces pain perception (Wiechula, 2003;Metzger, 2004;Leaper et al, 2012;Coutts et al, 2008;Feldman, 1991;...…”

Integrin-mediated regulation of epidermal wound functions

“…Surgical scar revision remains a mainstay therapy, although many other therapeutic approaches have been attempted (Reish and Eriksson, 2008). Interestingly, occlusive dressings have been effective in both controlled animals studies and prospective, randomized studies (Mustoe and Gurjala, 2011). Importantly, these dressings are thought to promote epidermal function by prompt restoration of barrier function, thereby reducing water loss and potentially reducing epidermal paracrine signals to inflammatory cells and other wound cells (Mustoe and Gurjala, 2011; Reish and Eriksson, 2008).…”

“…Interestingly, occlusive dressings have been effective in both controlled animals studies and prospective, randomized studies (Mustoe and Gurjala, 2011). Importantly, these dressings are thought to promote epidermal function by prompt restoration of barrier function, thereby reducing water loss and potentially reducing epidermal paracrine signals to inflammatory cells and other wound cells (Mustoe and Gurjala, 2011; Reish and Eriksson, 2008). Given the emerging roles for keratinocyte integrins in controlling epidermal paracrine signals, their potential roles in hypertrophic scarring should not be overlooked and warrants investigation.…”

Topical application of ALK5 inhibitor A-83-01 reduces burn wound contraction in rats by suppressing myofibroblast population

“…Occlusive dressings made of silicone gel are also being used to help scar maturation with reduced infection and hypertrophy although the outcomes of these interventions are not fully satisfactory. 5,6) It is generally accepted that the increase in the number of myofibroblast is directly associated with scar formation and wound contraction, and these cells are found in all contracted fibrotic tissues. [7][8][9] The α-smooth muscle actin (α-SMA) and extracellular matrix proteins, which are mainly produced by myofibroblasts, are responsible for the generation of the contractile force required for the contraction of scars.…”