label: Polyarteritis Nodosa
label_lc: polyarteritis nodosa
description: "A necrotizing vasculitis that affects medium-sized arteries, it is usually idiopathic, and may be triggered by viral infections (Hepatitis B, also others). A multisystem disease, it most commonly affects skin (nodules, livedo reticularis) and peripheral nerves; higher morbidity is associated with gastrointestinal, central nervous system, cardiac, and/or other organ involvement. Anti-neutrophil cytoplasmic antibodies (ANCA) are typically negative."