ABSTRACT
A. Clinical Definition Keloids are characterized by exuberant proliferation of collagen that extends beyond the confines of a wound. Growth of the lesion may continue for years without evidence of re gression. Histologically, keloids display increased mucinous ground substance, disarrayed eosinophilic collagen sheets, and relatively smaller quantities of fibroblasts (1-4). Hyper trophic scarring is also characterized by exuberant production of collagen but does not ex tend beyond the confines of the wound into adjacent normal skin. Hypertrophic scars have less mucinous ground substance and fewer fibroblasts. Furthermore, hypertrophic scars may resolve over time. Acne keloidalis nuchae is a related chronic inflammatory condition that is characterized by lesions in the occiput and nape of the neck with keloid-like lesions and often with purulent draining sinuses and fistulous tracts. Both acne keloidalis and true keloids are difficult problems to cure and often result in significant morbidity for the pa tient. There is no established animal model for keloid study, which further confounds po tential human investigational trials.
