Acute interstitial nephritis complicating a new diagnosis of Wegener's granulomatosis.

Establishing the underlying diagnosis in acute renal failure is essential in guiding patient management. To our knowledge, this is the first reported case with concurrent diagnoses of Wegener's granulomatosis and non-steroidal anti-inflammatory drug (NSAID)-induced interstitial nephritis. Renal biopsy should be performed in renal insufficiency patients where several concurrent conditions are suspected to obtain the correct diagnosis and institute appropriate treatment.