Is there evidence of renal parenchymal disease (other than acute tubular necrosis)?
Intrinsic renal disease other than acute tubular necrosis, although uncommon, must always be excluded as this has important management implications. The history and examination may reveal features of underlying systemic disease, such as rashes, arthralgia, or myalgia. Use of antibiotics and non-steroidal antiinflammatory drugs (widely available without prescription) should be specifically asked about, as these can cause acute interstitial nephritis. Urine dipstick and microscopy are mandatory to avoid missing a renal inflammatory process. Dipstick blood or protein, or dysmorphic red cells, red cell casts (suggestive of glomerulonephritis), or eosinophils (suggestive of acute interstitial nephritis) on microscopy, warrants prompt referral to a nephrologist.
