Efficacy of Topical Enalapril in Treatment of Hypertrophic Scars

Abstract

BACKGROUND Angiotensin II activation by angiotensin-converting enzyme (ACE) is a significant mediator in wound healing and collagen production. In this study, the effect of topical application of ACE on hypertrophic scar formation has been studied in a clinical trial. METHODS Thirty patients with hypertrophic scar and itching after treatment of 2nd or 3rd degree burns participated in this double-blinded clinical trial. Subjects had two same-degree scars on symmetrical sites of body which were randomly allocated into two groups. One side was treated with 1% enalapril ointment and the other side with placebo twice daily. During a 6-months follow-up, a scoring table for itching was completed on a daily basis by patients. Furthermore, a single surgeon measured size of scars once a month. The mean size, thickness and itching score were calculated for each scar and compared between medication and placebo-treated scars. RESULTS The mean size of scars in enalapril treated side was significantly less than scars in the placebo side. Additionally, enalapril treated scars had significantly lower itching scores compared to the placebo group. CONCLUSION Topical enalapril significantly decreases the clinical parameters of hypertrophic scar and also itching as an indirect indicative of scar improvement. Furthermore, enalapril proved to be clinically safe for patients with low incidence of adverse drug reactions and acceptable cost effectiveness.