Page 225 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

Polyarteritis Nodosa 201

11]. In France, the prevalence of PAN was 34 per 1,000,000 inhabitants in Seine–Saint-Denis,
a northern suburb of Paris [12].

The incidence of PAN has dramatically declined in parallel with HBV infection (3), and
is now very rare indeed. Public health measures including vaccine prophylaxis, blood-
transfusion safety and other prophylactic measures against infectious exposure have resulted
in the sharp drop in the annual number of PAN cases, suggesting a contributory infectious
etiopathogenesis. Although HBV infection is a known cause of PAN, other infectious agents
including viruses may be implicated in its onset.

Table 1. 1990 ACR Criteria for the Classification of Polyarteritis Nodosa*

Criterion Definition**

1. Weight loss >4 kg Loss of ?4 kg of body weight since illness began, not

due to dieting or other factors

2. Livedo reticularis Mottled reticular pattern over the skin of portions of

the extremities or torso

3. Testicular pain or tenderness Pain or tenderness of the testicles, not due to infection,

trauma or other causes

4. Myalgia, weakness or Diffuse myalgia (excluding shoulder and hip girdles),

polyneuropathy or weakness of muscles or tenderness of leg muscles

5. Mononeuropathy or Development of mononeuropathy, multiple

polyneuropathy mononeuropathy or polyneuropathy

6. Diastolic BP >90 mm Hg Development of hypertension with the diastolic BP

>90 mm Hg

7. Elevated BUN or creatinine Elevation of BUN >40 mg/dL (14.3 µmol/L) or

creatinine >1.5 mg/dL (132 µmol/L), not due to

dehydration or obstruction

8. Hepatitis B virus Presence of hepatitis B surface antigen or antibodies in

serum

9. Arteriographic abnormality Arteriogram showing microaneurysms or occlusions of

the visceral arteries, not due to arteriosclerosis,

fibromuscular dysplasia or non-inflammatory causes

10. Biopsy of small- or medium-sized Histological changes showing the presence of

artery containing neutrophils granulocytes or granulocytes and mononuclear

leukocytes in the artery wall

*Adapted from, reference [4].
**For classification purposes, a patient with vasculitis shall be said to have PAN if at least 3 of these 10

criteria are present. The presence of any 3 or more criteria yields a sensitivity of 82.2% and a
specificity of 86.6%. BP: blood pressure; BUN: blood urea nitrogen; kg, kilogram; mmHg,
millimeters of mercury.
Abbreviations: ACR, American College of Rheumatology; BP, blood pressure; BUN, blood urea
nitrogen.

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