Hereditary epidermolysis bullosa—the general term referring to perhaps as many as nine different 1 mechanobullous disorders of the skin—is a devastating disease to the patients and families afflicted with one of its genetic forms. During the past two decades, the investigations of dermatologists, geneticists, immunologists, and cell biologists have contributed substantially to our understanding of basic disease mechanisms in certain forms of epidermolysis bullosa. Because of this, it has been possible in some cases to take a more direct approach and to begin to tailor therapy to putative pathogenic mechanisms. Recessive dystrophic epidermolysis bullosa has been shown by ultrastructural 2,5 and biochemical 6-10 methods to be a disorder in which the pathogenesis of blistering is, at least in part, related to trauma-induced destruction of collagen in the papillary dermis. Based on the observation that human skin collagenase is overproduced in the skin of patients with this form of epidermolysis bullosa, 8