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

[OBJECTIVE] 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.

[MATERIALS AND METHODS] 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.

[RESULTS] 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.

[CONCLUSIONS] 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.