Objective:To evaluate the clinical effects of 5-fluorouracil in different mass concentrations combined with triamcinolone in the treatment of keloids.Methods:From March 2018 to March 2019, 29 patients with 31 keloids receipted in the Department of Plastic Surgery of Fujian Medical University Union Hospital, 11 patients with 20 keloids receipted in the Department of Dermatology of Pingtan Comprehensive Experimental Area Hospital, and 9 patients with 9 keloids receipted in the Fuzhou Heisey-Dea Aesthetic Clinic were included in this prospectively randomized control study, with 27 males and 22 females, aged (30±9) years. According to the random number table, the keloids were divided into low mass concentration group (19 keloids, 17 patients), medium mass concentration group (21 keloids, 19 patients), and high mass concentration group (20 keloids, 17 patients). Then 5-fluorouracil at mass concentrations of 0.5, 5.0, and 12.5 mg/mL combined with triamcinolone acetonide were injected respectively, once every 4 weeks, for a total of 3 times. Before the first treatment and in 3 months after the last treatment, the appearance of keloids was evaluated by Vancouver Scar Scale (VSS) and pain and pruritus of keloids were evaluated by Visual Analogue Scale (VAS). Then the score differences before and after the treatment were calculated. In 6 months after the last treatment, the patients' efficacy satisfaction was evaluated by efficacy satisfaction rating scale. Adverse reactions during the treatment were recorded. In the follow-up of one year after the last treatment, the recurrence rates of keloids were counted. Data were statistically analyzed with chi-square test, one-way analysis of variance, paired sample t test, least significant difference t test, Wilcoxon rank sum test, Kruskal-Wallis rank sum test, or Fisher′s exact probability test. Results:Before the first treatment, the appearance VSS scores of appearance of keloids in the three groups were similar ( F=0.039, P>0.05). In 3 months after the last treatment, the appearance VSS scores of keloids in low mass concentration group were significantly higher than those in medium mass concentration group and high mass concentration group ( t=2.267, 4.086, P<0.05 or P<0.01). In 3 months after the last treatment, the appearance VSS scores of keloids in low mass concentration group, medium mass concentration group, and high mass concentration group were significantly decreased compared with those before the first treatment ( t=18.222, 44.272, 22.523, P<0.01). The differences of appearance VSS scores of keloids in low mass concentration group before and after treatment were significantly lower than those in medium mass concentration group and high mass concentration group ( t=-4.096, -6.357, P<0.01), and the differences of appearance VSS scores of keloids in medium mass concentration group before and after treatment were significantly lower than those in high mass concentration group ( t=-2.368, P<0.05). Before the first treatment, the pain and pruritus VAS scores of keloids in the three groups were similar ( χ2=0.149, P>0.05). In 3 months after the last treatment, the pain and pruritus VAS scores of keloids in low mass concentration group were significantly higher than those in medium mass concentration group and high mass concentration group ( Z=2.191, 4.386, P<0.05 or P<0.01), and the pain and pruritus VAS scores of keloids in medium mass concentration group were significantly higher than those in high mass concentration group ( Z=2.276, P<0.05). In 3 months after the last treatment, the pain and pruritus VAS scores of keloids in medium mass concentration group and high mass concentration group were significantly decreased compared with those before the first treatment ( Z=-3.904, -3.844, P<0.01). The differences of pain and pruritus VAS scores of keloids in low mass concentration group before and after treatment were significantly lower than those in medium mass concentration group and high mass concentration group ( Z=-4.265, -6.104, P<0.01). In 6 months after the last treatment, the efficacy satisfaction scores of the corresponding patients of keloids were (88±8) points in high mass concentration group, which were significantly higher than (76±8) points in medium mass concentration group and (60±8) points in low mass concentration group ( t=-3.820, -6.675, P<0.01), and the efficacy satisfaction scores of the corresponding patients of keloids in medium mass concentration group were significantly higher than those in high mass concentration group ( t=-2.984, P<0.05). There was only statistically significant difference in pain within the 3 groups ( P<0.01). In the follow-up of one year after the last treatment, the recurrence rate of keloids in high mass concentration group was significantly lower than that in low mass concentration group ( χ2=8.313, P<0.01), and the recurrence rate of keloids in medium mass concentration group was similar to the recurrence rates in low mass concentration group and high mass concentration group ( P>0.05). Conclusions:After treating keloids with high mass concentration of 5-fluorouracil combined with triamcinolone acetonide, the symptoms were significantly improved, the efficacy satisfaction of patients was increased, with no obvious adverse reactions but long lasting efficacy. Their overall effects are better than treatment using medium and low mass concentrations of 5-fluorouracil, which is worthy of clinical promotion.