Acute interstitial nephritis. Why do the kidneys suddenly fail?

Acute interstitial nephritis is a clinical and pathologic entity with diverse causes. The most common cause at present is reaction to drug use, but infection, a concomitant uveitis syndrome, and other rare causes have been reported. Acute interstitial nephritis should always be considered in a patient with acute renal failure, because it is a treatable cause that may result in interstitial fibrosis and irreversible disease if not arrested.