Question category: Nephrology
A 45 year old female is admitted with cellulitus requiring IV antibiotics. She is commenced on IV benzylpenicillin and IV flucloxacillin. She is commenced on Diclofenac for pain. After 3 days she she develops pyrexia, arthralgia, maculopapular rash, haematuria and oliguria. Bloods reveal acute renal failure and eosinophilia. A renal biopsy reveals interstitial cellular infiltrate with eosinophils present and variable tubular necrosis. What is the most likely diagnosis?