Cutaneous Manifestations of Medium- and Large-Vessel Vasculitis.

Dermatologic manifestations are observed in almost all systemic vasculitides, even in large-and medium-vessel vasculitides, although such vessels are not found in the skin. Cutaneous manifestations may be related to a direct skin localization of the systemic vasculitis or a non-specific process associated with the vasculitis. According to the 2012 International Chapel Hill consensus, the two major variants of large-vessel vasculitides are Takayasu arteritis and giant-cell arteritis. In Europe and North America, acute inflammatory nodules or erythema nodosum-like lesions are the most commonly observed skin lesions with Takayasu arteritis. Medium-sized arteriole vasculitis of the dermis or subcutis but also septal or lobular panniculitis may be found during pathological examination. In Japan, widespread pyoderma gangrenosum-like lesions are more frequent. Cutaneous manifestations of giant-cell arteritis are rare; they are ischemic, linked to arterial occlusions, or non-ischemic, with various mechanisms. The two major medium-vessel vasculitides are Kawasaki disease and polyarteritis nodosa. Kawasaki disease is characterized by a mucocutaneous lymph node syndrome without skin vasculitis. Two subsets of polyarteritis nodosa with different skin manifestations are described, without transition from one to the other. In the systemic subset, the most frequent skin lesions are in the order of frequency purpura, livedo, and nodules. Cutaneous polyarteritis nodosa mainly features nodules, livedo racemosa, and ulcerations. Genetic screening and measurement of plasma levels of adenosine deaminase 2 should be considered for patients with uncommon systemic polyarteritis nodosa or early-onset cutaneous polyarteritis nodosa.