Medium Vessel Vasculitis

Polyarteritis Nodosa

General Principles


Polyarteritis nodosa (PAN) affects men more than women, typically between the ages of 40 and 60 years. Most of the cases are idiopathic and a minority are caused by hepatitis B virus infection.


Clinical Presentation

  • Most of the patients will have systemic symptoms such as fever, malaise, weight loss, arthralgias, and myalgias. Presentation may be nonspecific; it will depend on the organ systems affected. Some of the manifestations include the following:
    • Skin: erythematous nodules, purpura, livedo reticularis, ulcers
    • Renal: hypertension, perirenal hematomas, renal infarctions
    • Neurologic: typically, mononeuritis multiples. CNS involvement is exceedingly rare
    • Gastrointestinal: mesenteric arteritis leading to abdominal pain, melena, bloody or nonbloody diarrhea, and life-threatening gastrointestinal bleeding
    • Cardiac: narrowing or occlusion of coronary arteries leading to myocardial ischemia and heart failure
    • Musculoskeletal: myalgias and muscle weakness
    • Reproductive: orchitis, testicular tenderness
    • Ocular: ischemic retinopathy or optic neuropathy
  • Limited cutaneous PAN is a term used for isolated skin involvement which rarely converts into systemic PAN. Isolated single-organ PAN can also occur; it is considered a monocyclic disease that rarely relapses.

Diagnostic Testing

  • Laboratory findings, just like in other vasculitis, include anemia of chronic disease, and elevated ESR and CRP. A small percentage of patients may have eosinophilia. Hematuria may be present, but no active urine sediment and hepatitis serologies should be checked as well.
  • Angiography, typically mesenteric, renal, or coronary, is often diagnostic. These demonstrate microaneurysms and/or stenoses in small to medium size vessels.
  • Biopsy should be pursued whenever possible. Skin, nerve, muscle, or testicle biopsies may be easily accessible and provide diagnosis.


  • Glucocorticoids are considered first-line treatment. In patients with severe, life-threatening manifestations (creatinine > 1.5 mg/dL, cardiomyopathy, GI or CNS involvement), pulse intravenous methylprednisolone 1000 mg daily for 3–5 days is recommended. In patients without these manifestations, oral prednisone at 1 mg/kg is commonly started.
  • Patients with severe manifestations or those with mild disease but unable to be tapered off steroids should be started on additional treatment. Cyclophosphamide is considered first line; if not tolerated or disease is resistant, other medications should be considered including rituximab, methotrexate, azathioprine, or mycophenolate mofetil.
  • Hepatitis B–associated PAN treatment is based on the treatment of the infection with antivirals. Patients with severe manifestations can be started on glucocorticoids and plasma exchange until antiviral therapy becomes effective.

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