Diseases,it seems, have lives of their own, both in the concrete terms of their natural history in an affected individual and in the abstract terms of their definition as clinical entities. As clinical entities, the criteria that are developed through observation and investigation and that are used to define specific diseases can be likened to the characteristics and behaviors that define an individual over time. "Identity crises" are not uncommon, and they are often essential elements in the maturation of our understanding of the biologic and pathophysiologic processes involved. Perhaps because of their relative infrequency or perhaps because of inherent complexity, some diseases seemingly experience a "prolonged adolescence" in which a well-defined identity is more elusive and evolves over a somewhat more tortuous and even contradictory path. Such a situation may be said to apply to epidermolysis bullosa acquisita (EBA). While laboratory investigations in recent years have more clearly defined