Livedo reticularis (LR) is a well-known, relatively common physical finding consisting of macular, violaceous, connecting rings that form a netlike pattern (Fig 1). In most cases, it is a completely benign finding related to cold exposure. However, there are many potential causes (Table I), and this can make the evaluation of a patient presenting with this finding very difficult. An excellent review of the topic by Fleischer and Resnick was published in 1990. We have endeavored to update the literature and provide clinicians with guidance regarding the evaluation and treatment of patients presenting with LR.