Table 1

Criteria for relapsing disease20

Manifestations have to be new or recurrent findings:
(a)  Progressive glomerulonephritis, that is, a decrease in renal function of 30% or more within 3 months in combination with (microscopic) haematuria or evidence of acute necrotising lesions on renal biopsy.
(b)  Pulmonary infiltrates with or without cavitation with rising C reactive protein concentrations either with necrotising granulomatous inflammation or necrotising vasculitis on biopsy, or—when no histological proof can be obtained—after exclusion of infection and malignancy.
(c)  Sinusitis, otitis, ulceration of nasal mucosa, or a nasal proliferative mass, in combination with necrotising granulomatous inflammation on biopsy.
(d)  Miscellaneous: progressive mononeuritis multiplex, cranial nerve palsy, cerebral vasculitis, necrotising scleritis, orbital pseudotumor, progressive tracheal stenosis with active disease on biopsy, peripheral gangrene, necrotising vasculitis of medium sized or small muscular arteries.