Livedo reticularis and related disorders.

OPINION STATEMENT: Livedo reticularis is a violaceous mottling of the skin with a "fishnet" reticular appearance. Primary and secondary etiologies exist, including a pathologic variant termed livedo racemosa. No evidence-based medicine exists to guide therapy for this disorder, but most patients with primary and secondary livedo reticularis are asymptomatic and do not require treatment. In the rare instance that a patient with primary livedo reticularis experiences mild symptoms such as episodic numbness and tingling, avoidance of cold and vasoconstricting substances should be encouraged. Lastly, judicious dosing of a vasodilator such as a calcium channel blocker can be prescribed. Patients with secondary livedo reticularis or livedo racemosa may benefit from these same therapeutic suggestions; however, treating the proximate cause of livedo with a systemic association is encouraged and is most likely to yield cutaneous improvement. Although antiplatelet and/or anticoagulant therapy is often required when treating a patient with the antiphospholipid antibody syndrome or Sneddon's syndrome, the attendant livedo racemosa typically remains unchanged or progresses despite this treatment.