Other Vasculitic Syndromes
Although rare, some other vasculitic syndromes, including polyarteritis nodosa and Wegener's granulomatosis, may occur in elderly persons. They are more common among men than among women.
Polyarteritis nodosa (polyarteritis, periarteritis nodosa) is characterized by segmental inflammation and necrosis of medium-sized muscular arteries, with secondary ischemia of tissue supplied by affected vessels. Wegener's granulomatosis, which resembles polyarteritis nodosa, usually begins as a localized granulomatous inflammation of upper or lower respiratory tract mucosa and may progress into generalized necrotizing granulomatous vasculitis and glomerulonephritis.
The cause is unknown, but immune mechanisms appear to be involved because immune complexes are occasionally found in vessel walls and glomeruli. One hypothesis suggests that these syndromes are the result of a respiratory tract hypersensitivity reaction.
Symptoms and Signs
Symptoms and signs are nonspecific; fever, malaise, anorexia, weight loss, purpura, arthritis, central nervous system dysfunction, and infarction of various organs are common. Some degree of renal involvement occurs in 70 to 90% of patients; progressive renal failure can be a late manifestation in polyarteritis nodosa. The presentation of these vasculitic syndromes often mimics that of other disorders. Patients with Wegener's granulomatosis often present with upper respiratory complaints, including sinusitis, nasal mucosal ulcerations, and serous or purulent otitis media with hearing loss, cough, hemoptysis, and pleuritis.
Diagnosis, Prognosis, and Treatment
Diagnosis is often difficult because of the varied presentation and because pathologic findings are usually absent. Renal biopsy can confirm the presence of glomerulonephritis. Polyarteritis nodosa may be diagnosed by evidence of organ involvement on biopsy or of multiple aneurysm formation on arteriography. Wegener's granulomatosis may be diagnosed by using pulmonary or respiratory tract biopsy. Some experts recommend the use of antinuclear cytoplasmic antibody (ANCA) as a diagnostic test for Wegener's granulomatosis, but others question ANCA's usefulness because of its poor specificity.
Prognosis is very poor for both disorders, if untreated. Early diagnosis and aggressive treatment are necessary to prevent progression to end-organ damage (eg, end-stage renal disease). High-dose corticosteroids produce remission in some patients with polyarteritis nodosa, but they must be used long-term. Other measures include immunosuppressants, antihypertensive therapy, careful fluid management, attention to renal impairment, and blood transfusion. Cyclophosphamide is the treatment of choice for Wegener's granulomatosis. |