Polyarteritis Nodosa (PAN)

Epidemiology

Mean age of onset: 45 y/o
M:F ratio: 2.5:1
Associated with: Hepatitis B

Physiology

Systemic necrotizing vasculitis of small and medium-sized arteries (with neutrophilic inflammation of blood vessels and perivascular space)
Tissue ischemia and infarction/aneurysmal dilatation of blood vessels

Diagnosis

CBC: leukocytosis (75%)
HBsAg: positive in 30% of cases
ABG: elevated A-a gradient
PFT’s: decreased DLCO, increased Vd/Vt ratio
p-ANCA: may be positive (diffuse granular pattern)
Angiogram: aneurysms of small and medium-sized arteries
Skin Bx (vasculitic lesions): diagnostic

Clinical Manifestations

Rheumatologic Manifestations (64% of cases)

Myalgias

Renal Manifestations (60% of cases)

Vasculitis
Glomerulonephritis
Hypertension (60% of cases)

Hepatic Manifestations (44% of cases)

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Dermatologic Manifestations (43% of cases)

Cutaneous Nodules
Skin Ulcers
Livedo Reticularis

Cardiac Manifestations (36% of cases)

Coronary Arteritis

Neurologic Manifestations (23% of cases)

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Pulmonary Manifestations (usually spared)

Diffuse Alveolar Hemorrhage (DAH) (see Diffuse Alveolar Hemorrhage): rare case reports

Treatment

Cytotoxic Agents

References

Hepatitis B-Related Polyarteritis Nodosa Complicated by Pulmonary Hemorrhage. Chest 2001; 119: 1608-1610