Abstract:
Keloid and hypertrophic scars occur from abnormal responses in any phases of the wound healing process. To this day, the exact pathophysiology of keloid and hyperthrophic scars formation is still unknown, so it is difficult to encounter an effective treatment strategy for these patients. A variety of treatments for keloid and hypertrophic scars have been advocated in the past. The results were inconstant and recurrences have remained common. Intralesional botulinum toxin A was found to be effective in keloid and hypertrophic scars treatment. Because of its extensive use and fewer complications, so botulinum toxin A has become an interesting alternative treatment for keloid and hypertrophic scars.
Objective to compare the efficacy of 3 U/CM3 and 5 U/CM3 botulinum toxin A injections for treatment of keloid and hypertrophic scars.
Methods and Materials A total of 16 keloid and hypertrophic scars after a cesarean section were performed in this the study. Each scar was divided into three portions (two lateral portions were subjected to study) and received monthly treatments. One side with intralesional botulinum toxin A injections 3 unit/cm3, and the other side with intralesional botulinum toxin A injections 5 unit/cm3. The primary outcome was assessed by melanin value by Maxemeter®MX18, The Vancouver Scar Scale (VSS) and volume of keloid and hypertrophic scars at 0, 4, 8 and 12 weeks, consecutively. Secondary outcome was assessed by patient satisfaction and side-effects.
Results in the group treated with intralesion botulinum toxin A 3 U/cm3 and 5 U/cm3 showed a statistically significant decrease of melanin value, VSS score and volume of scars compared with the baseline. Regarding the patient satisfaction score, there was no significant difference between both groups and no adverse effect was observed.
Conclusion Intralesional Botulinum toxin A 3 unit/cm3 injection can reduce melanin value, VSS score and the volume of scars with significant difference compared with the baseline and no significant difference compared with 5 unit/cm3 injection after 12 week. This finding suggests that intralesional botulinum toxin A 3 unit/cm3 injection has the efficacy to inhibit the proliferation of fibroblasts resulting in decreasing the volume of keloid and hypertrophic scars. In addition, it reduces melanin synthesis resulting in decreasing the melanin value. Thus, Intralesional Botulinum toxin A 3 unit/cm3 injection has effectiveness in keloid and hypertrophic scars treatment.