Systemic necrotizing vasculitis with renal involvement accompanied by remarkable eosinophilia: a case with overlapping features of polyarteritis nodosa and allergic granulomatous angiitis.

A 71-year-old woman was clinically suspected of allergic granulomatous angiitis (AGA) because of preceding allergic diseases including bronchial asthma, remarkable eosinophilia (14,300/mm3), mononeuritis multiplex, positive rheumatoid factor, elevated serum immunoglobulin E, and eosinophilic inflammation of the kidney. Autopsy findings, however, were characterized of polyarteritis nodosa (PAN). Necrotizing angiitis was present in several organs except for the lung; focal and segmental glomerular lesions with crescent formation were observed in the kidney, and granuloma formation was not found. This case may be an intermediate type between PAN and AGA (an overlap syndrome) and provide useful information on the clinical entities of systemic necrotizing vasculitis.