Comparison of Ultrasound-Assisted Low-Dose Versus Medium-Dose 5-Fluorouracil and Triamcinolone Acetonide in the Treatment of Hypertrophic Scar

Intralesional 5-fluorouracil (5-FU) and triamcinolone acetonide (TAC) injection is effective for the treatment of hypertrophic scar. The side effects of current that recommended 45 mg/ml (high-dose) 5-FU have been reported. However, no previous study has investigated the efficacy and safety of low-dose (2.5 mg/ml) 5-FU with 4 mg/ml TAC or medium-dose (10 mg/ml) 5-FU with 4 mg/ml TAC for treatment of hypertrophic scar. Herein, a retrospective comparative study was conducted. The records of 70 patients, treated with low-dose (2.5 mg/ml) 5-FU and 4 mg/ml TAC every 4 weeks (Group 1) or medium-dose (10 mg/ml) 5-FU and 4 mg/ml TAC every 4 weeks (Group 2), were analyzed. The Vancouver Scar Scale (VSS), vascularity, and thickness of hypertrophic scar at baseline and at 7th-treatment (each group received 6 treatment sessions) were compared. The ultrasound showed the large vascular distribution in scar margins. Both groups gained clinical improvement in VSS, vascularity, and thickness. Group 2 (medium-dose) exhibited significantly better improvement than Group 1 (low-dose). However, the overall side effects rate was 11.4% in Group 1, significantly lower than 31.4% in Group 2. Scar margins were suggested to be target sites for injection. Medium-dose (10 mg/ml) 5-FU + 4 mg/ml TAC could effectively reduce the thickness of hypertrophic scar; however, the side effects rate was also higher in medium-dose group than in low-dose group.