Intralesional treatments for hypertrophic scars: comparison among corticosteroid, 5-fluorouracil and botulinum toxin in rabbit ear hypertrophic scar model.

Different treatment modalities have been used either alone, or in combination to achieve an optimum improvement for hypertrophic scars. Intralesional injections of corticosteroids and 5-fluorouracil are among the most commonly used treatments. Recently, botulinum toxin is proposed as a new treatment option. In this study, it is aimed to compare the efficacies of intralesional triamcinolone acetonide, 5-fluorouracil and botulinum toxin-A for hypertrophic scars. In order to minimize the variables affecting scar formation, standardized wounds in rabbit ear hypertrophic scar model was used.Four surgical wounds were created on both ears of eight rabbits. Injections to be compared (triamcinolone acetonide, 5-fluorouracil, botulinum toxin-A and control) are administered intralesionally to established scars on day 30. Scars were harvested on day 60 for morphometric analysis including hypertrophic index, fibroblast density, and relative collagen density.Triamcinolone acetonide and 5-fluorouracil injections decreased hypertrophic indexes significantly compared to botulinum toxin-A and control group. However, only 5-fluorouracil was effective to reduce fibroblast counts significantly. No statistically significant differences were found between the treatment groups in terms of collagen index.According to the results of our study, triamcinolone acetonide and 5-fluorouracil are comparatively effective as monotherapy, but botulinum toxin-A was not effective on established hypertrophic scars.