Sarcoidosis, Legionella, leptospirosis, Streptococcus, viral infections, and certain Chinese herbs may also be responsible. Symptoms, Signs, and Diagnosis Onset after drug therapy may be as long as several weeks after a single exposure or as soon as 3 to 5 days after a second exposure. Presentation of acute tubulointerstitial nephritis varies, but acute renal failure, with or without oliguria, temporally related to an offending drug or infection is typical. Fever occurs in most cases and may be accompanied by an urticarial rash. The urine sediment usually reveals WBCs, RBCs, and WBC casts but is occasionally bland.
Proteinuria is usually minimal.
The kidneys usually are large because of interstitial edema and avidly take up radioactive gallium or radionuclide-labeled WBCs. However, a negative radionuclide scan with gallium-67 does not preclude the diagnosis. Diagnosis involves stopping the suspected offending drug and observing the response. No further evaluation is required if renal function begins to improve within several days. Glomeruli usually are normal.