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. 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. Prognosis is very poor for both disorders, if untreated. 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.