A comprehensive evidence-based review on the role of topicals and dressings in the management of skin scarring

Abstract

Wound healing after dermal injury is an imperfect process, inevitably leading to scar formation as the skin re-establishes its integrity. The resulting scars have different characteristics to normal skin, ranging from fine-line asymptomatic scars to problematic scarring including hypertrophic and keloid scars. Scars appear as a different colour to the surrounding skin and can be flat, stretched, depressed or raised, manifesting a range of symptoms including inflammation, erythema, dryness and pruritus, which can result in significant psychosocial impact on patients and their quality of life. In this paper, a comprehensive literature review coupled with an analysis of levels of evidence (LOE) for each published treatment type was conducted. Topical treatments identified include imiquimod, mitomycin C and plant extracts such as onion extract, green tea, Aloe vera, vitamin E and D, applied to healing wounds, mature scar tissue or fibrotic scars following revision surgery, or in combination with other more established treatments such as steroid injections and silicone. In total, 39 articles were included, involving 1703 patients. There was limited clinical evidence to support their efficacy; the majority of articles (n = 23) were ranked as category 4 LOE, being of limited quality with individual flaws, including low patient numbers, poor randomisation, blinding, and short follow-up periods. As trials were performed in different settings, they were difficult to compare. In conclusion, there is an unmet clinical need for effective solutions to skin scarring, more robust long-term randomised trials and a consensus on a standardised treatment regime to address all aspects of scarring.

Fig. 1

A representation of different types of skin scarring and scar types, as often observed, for example following a mid-sternal incision, post-cardiac surgery. a Fine-line scar, b hypertrophic scar, c intermediate raised dermal scar, d keloid scar

Fig. 2

A proposed flowchart indicating the different stages of the scar management timeline, as recommended by the corresponding senior author. A structured clinical assessment is required, taking into consideration patient medical and family history, including current signs and symptoms and utilising a range of quantitative and qualitative measurements in order to enable a targeted treatment, which may evolve over time as signs and symptoms change

Fig. 3

A flowchart depicting the effect of silicone gel and sheeting [1, 26, 92, 97, 117], vitamin E [36, 55, 66, 120], Aloe vera [39, 51, 67, 72], green tea [29, 40, 48, 71, 88, 109, 119, 121], onion extract [14, 24, 27, 31, 32, 34, 42, 43, 56, 59, 63, 65, 69, 79, 87, 91, 116], mitomycin C [6, 30, 53, 94, 96, 98, 103, 106, 110] and imiquimod [–12, 23, 33, 73, 76, 89, 93, 105] at addressing symptoms commonly cited during wound healing, skin scarring and problematic abnormal raised dermal scarring such as keloid and hypertrophic scarring. The symptoms best targeted by the treatment are indicated, as well as the known mechanistic target and resulting effect in vivo