Churg-Strauss syndrome presenting with acute renal insufficiency accompanied by eosinophilic tubulointerstitial nephritis.

We encountered an unusual and rare case of 59-year-old woman with Churg-Strauss syndrome (CSS) showing myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA)-related acute renal insufficiency accompanied by eosinophilic tubulointerstitial nephritis. To date, reports in English of CSS presenting with rapidly progressive/acute renal insufficiency and biopsy-proven renal lesions have been uncommon. Here, we discuss this unusual case and review the previously reported CSS cases. The complication of eosinophilic tubulointerstitial nephritis in CSS cases with acute renal insufficiency might be higher than generally thought. Furthermore, the presence of eosinophilic infiltration and eosinophilic tubulointerstitial nephritis might be associated with the good renal outcome in CSS patients.