Effectiveness of topical zinc oxide application on hypertrophic scar development in rabbits

Abstract

Background: The etiology, biology, prevention and effective treatment of hypertrophic scars have not exactly been defined. Topical zinc oxide application was shown to be effective in the treatment of proliferative scars. We studied the effectiveness of topical zinc oxide ointment in the prevention of hypertrophic scar development by using the rabbit ear hypertrophic scar model.

Methods: Circular full-thickness skin excisions were performed on both ears of 10 rabbits. The rabbits were divided into two groups and topical 40% zinc oxide ointment was applied daily to one ear and the ointment base was applied as placebo to the other ear. Scar samples were taken in the 3rd week in group 1 and in the 6th week in group 2. All of the specimens were divided into two halves: one half for histopathologic/histomorphometric examinations and the other half for biochemical studies.

Results: Application of topical zinc oxide ointment decreased clinical scar hypertrophy scores significantly (p=0.017) at 6th week in comparison with placebo. Topical zinc oxide also reduced nodule formation histopathologically at 6th week in comparison with placebo but this was not significant statistically (p>0.05).

Conclusion: The findings of this study may have clinical implications on the management of human hypertrophic scars.