Treatment of traumatic hypertrophic scars and keloids: a systematic review of randomized control trials

Exaggerated healing and remodeling after skin injury may cause hypertrophic and keloidal scars, which are associated with functional and quality of life impairment. There is limited guidance available regarding the relative effectiveness of therapies for hypertrophic scars and keloids. In this review, we aim to compare the effectiveness of treatments for hypertrophic scars and keloids. MEDLINE, Embase, Scopus, and the Cochrane Collaboration database were searched from inception to March 2019 for randomized control trials of treatments for hypertrophic and keloid scars that included 20 or more patients. Outcomes evaluated included the standardized mean reduction in scarring and adverse events. The type of scar and the demographic features were analyzed for their effect on clinical outcome. Based on 25 included clinical trials, intralesional injection (64.1% [95% CI 60.8-67.5%]) may be more effective than physical (29.9% [95% CI 28.9-30.9%]) or topical treatments (34% [95% CI 31.8-36.8%]). Combination of 5-fluorouracil and triamcinolone (9:1 dilution) appeared superior among intralesional treatments for keloids. Ablative laser and pulsed-dye laser were the most useful laser treatments. Regression modeling showed laser treatment response was linked to Fitzpatrick skin type (p = 0.002). Adverse events were uncommon for all treatments and mostly transient. Intralesional treatments for keloid and hypertrophic scars may be the most reliable treatment option to improve pathologic scars, while laser treatment may have specific benefits for Fitzpatrick skin types I-III over types IV-VI. Management of pathological scars is an area of critical need, where appropriate treatment can have a significant impact on quality of life.