Polyarteritis nodosa is characterized by necrotizing inflammation that most commonly involves the medium muscular arteries, especially at their branch points.
The resulting ischemia can affect multiple organ systems:
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Nervous system involvement often produces mononeuritis multiplex or asymmetric polyneuropathy; sensory and motor deficits of the
median,
ulnar, and
fibular nerves are common.
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Renal involvement can lead to hypertension, oliguria, and even renal failure.
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Gastrointestinal involvement can produce pain and malabsorption; when larger vessels, such as the
celiac trunk or its branches are affected, fatal aneurysms can develop.
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Skin manifestations can take various forms, including livedo reticularis (which presents as a purplish lace-like pattern), ulcers, subcutaneous nodules, or even gangrene.
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Heart failure can occur due to
coronary artery obstruction.
Polyarteritis nodosa can be systemic or cutaneous.
Some secondary forms are related to
hepatitis B and C infections, or to
rheumatoid arthritis.
Most commonly affects men over 50 years of age.