Thus, suspicion should be high when the following are present: Typical symptoms or signs Risk factors, particularly a temporal relationship between onset and use of a potentially causative drug Characteristic urinalysis findings, particularly sterile pyuria Modest proteinuria, usually < 1 g / day (except with use of nonsteroidal anti-inflammatory drugs [NSAIDs], which may cause nephrotic-range proteinuria, 3.5 g / day) Evidence of tubular dysfunction (eg, renal tubular acidosis, Fanconi syndrome) Concentrating defect out of proportion to the degree of renal failure Eosinophiluria cannot be relied upon to make or exclude the diagnosis.