Effects of pharmacologic agents on human keloids implanted in athymic mice. A pilot study.

The treatment of keloids remains difficult. In experimental studies, lathyrogenic agents and colchicine have been shown to be effective in keloid prevention. Recently, a study was published of a new animal model utilizing human keloids implanted in athymic mice. We used the same model to compare the effects of penicillamine, acetylcysteine, colchicine, and triamcinolone acetonide. Unexpectedly, all keloids implanted showed a growth peak at 4 weeks and then regression in size. Histologic sections of the implanted keloids revealed peripheral vascularity, collagen bundles similar to the parent keloids, and no evidence of implant rejection. After 8 weeks, the mice treated with the lathyrogenic agents exhibited a higher rate of regression when compared with the control mice. While triamcinolone acetonide may have prevented keloid implant growth, drug toxic reaction may have been a factor.