Polyarteritis nodosa

• 多發性動脈炎（PAN） 是:一種全身性壞死血管炎，最初於 1866 年由 Adolph Kussmaul  和  Rudolph Maier 描述

• 它通常影響中型動脈血管，但也可以 󰶻 影響小型動脈血管

• 不像其他小型動脈血管炎，多發性動脈炎並  不通常  與  抗中性粒細胞質抗體（ANCA）相關

• 一種全身性疾病過程，儘管存在  一種稱 為:皮膚多發性動脈炎（CPAN）的  疾病有限形式

• Usually middle-aged males.

• Hepatitis B seropositivity in 30% of patients.

  • Fever,
  • weight loss,
  • malaise,
  • headache.

• GI: abdominal pain, melena.

• Hypertension, neurologic dysfunction, cutaneous eruptions, renal damage.

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(“classic” PAN) (Nat Rev Rheumatol 2017;13:381)

• Necrotizing nongranulomatous vasculitis of medium & small arteries (w/in muscular media) w/o glomerulonephritis or capillary involvement (ie, no DAH), not a/w ANCA
• Incidence ~2/million/y; ↑ in HBV-endemic areas; ♂ >♀; av. age ~50; 10% HBV-assoc
• Clinical manifestations of Polyarteritis nodosa
• Dx (Arthritis Care Res 2021;73:1061): ↑ ESR/CRP; r/o ANCA, HBV; ↓ C3/C4 if HBV-assoc.

Angiogram

• (mesenteric or renal vessels) → microaneurysms & focal vessel narrowing
• string of beads on angiogram CTA or MRA may be adequate for dx, but conventional angiogram is 󰶻most sensitive Biopsy (nerve, deep-skin, or affected organ) → vasculitis of small and medium a. w/ fibrinoid necrosis w/o granulomas
• Rx: based on severity; steroids ± DMARD (MTX, AZA; CYC if severe); antivirals if HBV. Most dis. monophasic so consider stopping DMARD if in steroid-free remission at 18 m.