Occlusive cutaneous vasculopathies: rare differential diagnoses.

In addition to erythematous plaques, nodules, ulcerations, and necrosis, retiform purpura and livedo racemosa are indications of occlusive cutaneous vasculopathies. In contrast to cutaneous vasculitis, occlusive cutaneous vasculopathies primarily lead to vascular occlusion of the skin and only secondarily to signs of vascular inflammation. The lower legs are typically affected, but especially in the presence of acral skin changes, occlusive cutaneous vasculopathies should also be considered. Various stimuli can trigger occlusive cutaneous vasculopathies, including systemic or vascular coagulopathies, emboli, platelet or erythrocyte aggregates, cold-dependent gelling and agglutination of immunoglobulins, or, less commonly, medications.