Almost no subject in dermatology is as dizzying to a student of dermatology as that of "livedo vasculitis." One has only to start with usage of the terms "livedo," "livedo racemosa," and "livedo reticularis" about which there is no unanimity at all in the community of dermatology, not to speak about the relationship (or not) of these conditions to "livedo vasculitis" and "atrophie blanche." Terms introduced more recently such as "livedoid vasculitis" or the acronymic designation "PURPLE" do nothing to clarify the issue. Equally confusing are criteria for diagnosis of "livedo vasculitis," "livedo racemosa," and "livedo reticularis" both clinical and histopathologic, because they vary from article to article and from textbook to textbook. The befuddlement peaks when colleagues engage in discussions about whether "livedo vasculitis" is a "true" vasculitis or a "vasculopathy," usually without any attempt being made to definition of these latter terms.

In this series, we will address all the issues confusing about the condition, step by step. In this, the first part of this series, we elaborate on all terms associated with "livedo" and with "livedo vasculitis" in perspective historical. In future issues of this journal we will illuminate findings clinical and histopathologic of "livedo vasculitis" (part II) and considerations about pathogenesis and etiology (part III). We hope to elucidate the matter in a way instructive and comprehensible.