The distribution of hyaluronan in human skin and mature, hypertrophic and keloid scars.

A hyaluronan-binding protein (HABP) was used to locate the distribution of HA in normal skin and in various types of scar tissue: mature scar tissue, hypertrophic scar tissue and keloids. The study was intended to establish whether or not a deviant HA distribution could explain the different clinical features of these scar tissues. The distribution of HA was found to differ between the various scar tissues. In normal skin an intense HA-staining was observed in the papillary dermis. In mature scar tissue the distribution of HA resembled that of normal uninjured tissue, but the layer of HA was thinner. In hypertrophic scar tissue, HA occurred mainly as a narrow strip in the papillary dermis. Keloid tissue showed the least HA-staining of the papillary layer and resembled that of the bulging reticular dermis. In contrast, the thickened granular and spinous layer of the keloid epidermis exhibited an intense HA-staining. We suggest that the altered distribution and amount of HA in these different scar tissues may contribute to their different clinical characteristics. This histochemical technique for the demonstration of HA in scar tissue could be of use in clinical work to decide on therapeutic strategies.