The term "livedo racemosa" was coined by Ehrmann in 1907 [8] to describe lightning-shaped macular lesions with a bluish red color fading at the periphery of the lesions and merging into the adjacent skin. Livedo racemosa, translated from the Latin, designates a pale bluish macule of the skin that assumes a ramified shape that resembles the branches of a tree. Ehrmann emphasized that macules of livedo racemosa were not responsive to warming the skin because they are not the consequence of vasospasms as it is the case in livedo reticularis (see also livedo reticularis.) Livedo racemosa is always a sign of a pathologic process involving small vessels of the dermis. The same pattern can be produced by deposits of fibrin in vessel walls, by thrombi in the lumen of vessels, by calciphylaxis, by cholesterol emboli, and by an intravascular lymphoma. It is not surprising, therefore, that a variety of disorders of coagulation may produce the pattern of livedo racemosa in the skin.

In the literature of dermatology written in English, the terminology has become confusing in the past decades, especially since Champion used the term livedo reticularis as a generic one for all kinds of livid macules with branched as well as netlike shapes (Figs. 1A–C). [3] Livedo reticularis has commonly come to be used interchangeably with livedo racemosa in the literature of dermatology written in English. A variety of subclassifications of livedo reticularis (e.g., "transient" and "persistent" or "systemic" and "idiopathic" or "blanchable" and "necrosing") have been suggested for clarification, but actually have produced even more confusion.