Churg-Strauss syndrome with a clinical condition similar to IgG4-related kidney disease: a case report.

A 68-year-old Japanese woman with asthma of recent onset and a long history of membranous glomerulonephropathy (MN) was admitted because of multifocal pulmonary infiltrates, marked eosinophilia, mild renal dysfunction, a rash on her feet, and right median nerve paralysis. Although MPO- and PR3-ANCA were negative, skin biopsy demonstrated leukocytoclastic vasculitis and Churg-Strauss Syndrome (CSS) was diagnosed. She also had salivary gland swelling and a high serum IgG4 level. Renal biopsy revealed MN with eosinophil-rich tubulointerstitial nephropathy. Her symptoms resolved after the start of corticosteroid therapy. The present case shows that ANCA-negative CSS can have a clinical condition similar to IgG4-related kidney disease.