Collagen polymorphism in human scars.

: Collagen similar to the collagen found in embryonic skin (same intermolecular cross-links and same structure of the polypeptide chains) is synthesized in young human scars. Later on, in normal scars, this collagen is replaced by the collagen of adult skin progressively. In contrast, in hypertrophic scars, a high proportion of collagen of "embryonic" type is present permanently. In granulation tissues of chronic inflammation, experimentally developed in rats, similar "embryonic" collagen has been found ; these granuloma are proposed as a model in laboratory animals of human hypertrophic scars.