Silver Sulfadiazine Retards Wound Healing and Increases Hypertrophic Scarring in a Rabbit Ear Excisional Wound Model

This study evaluated the effects of topical use of silver sulfadiazine cream (SSD) on wound healing and subsequent scarring in a rabbit ear wound model. Seven millimeter full-thickness excisional wounds were created in rabbit ears. Twenty-four rabbits were randomized into four groups in which each group received base cream, 0.01% SSD, 0.1% SSD, or 1% SSD, respectively. Each treatment was applied at 2-day intervals from postoperative days (PODs) 2 to 14. At POD 7, half of the rabbits from each group were killed and tissues were harvested to measure wound healing parameters that included epithelial gap and granulation area. At POD 28, the remaining rabbits from each group were assessed for hypertrophic scarring. Epithelial gaps in SSD-treated groups at concentrations of 0.1 and 1% were significantly larger than those of base cream-treated controls. In contrast, analysis of granulation areas that represent volume of granulation tissue formed during healing did not show any statistical differences between the base cream-treated group and all three SSD-treated groups. At POD 28, when compared to the base cream-treated group (1.44 +/- 0.03), SSD-treated-groups (0.1 and 1%) had more (P <.05) hypertrophic scar formation (scar elevation index = 1.65 +/- 0.04, 0.1%; 1.63 +/- 0.06, 1%). The results of this study demonstrate that SSD treatment contributes not only to impaired reepithelialization but also to a greater hypertrophic scar formation. These results also indicate that caution should be exercised when using SSD clinically to prevent or treat wound infections.