The use of 4 % hydroquinone, 0,1 % retinoic acid and 0,1 % betamethasone creams to prevent hypermigmentation of partial-thickness skin grafts in long evans rats

ABSTRACTTHE USE OF 4 % HYDROQUINONE, 0,1 % RETINOIC ACID AND 0,1 % BETAMETHASONE CREAMS TO PREVENT HYPERMIGMENTATION OF PARTIAL-THICKNESS SKIN GRAFTS IN LONG EVANS RATSThe skin grafts are valuable alternative for the wounds that are not suitable for direct closing. The skin grafts are completely removed from their blood supply and moved to another area together with all its epidermis and some or all of its dermis. Aesthetic appearance is an important issue in closing of the wounds. Although graft darkening is expected to occur later in time, patients feel uncomfortable with its aesthetic appearance. Some data exist in the literature regarding the treatment of graft darkening. But there is no data about the prevention of it aside from avoiding from sunlight exposure in the first six monthsThe aim of this study is to prevent hyperpigmentation of skin graft of the Long Evans rats and to adapt this model for humans.The study included a total of 17 Long Evans rats, 8 rats as study group and 9 rats as control group. Partial-thickness skin graft was applied to the back of all animals. Creams containing 4 % hydroquinone, 0,1 % retinoic acid and 0,1 % betamethasone were applied twice daily to skin grafts of the study group on 15th postoperative day with a duration of 60 days. The control group did not receive any treatment. Effect of therapy was assessed visually with Melasma Severity Scale (MSS) on postoperative 45th and 75th days, and with histopathologically by biopsy on postoperative 75th day. The median value of MSS score at 45th day in our study was 1.33 in the control group and 1.00 in the study group. The median value of MSS score at 75th day was 1.00 in the control group and 0.66 in the study group. The median value of S100 score was 3.00 in the control group and 2.00 in the study group. The median value of MF score at was 3.00 in the control group and 2.00 in the study group. Hyperpigmentation was found to be lesser both visually and histopathologically in the study group. Findings our study concludes that this therapy could prevent graft hyperpigmentation in rats.Keywords: Long Evans rat, graft, hyperpigmentation, prevention