genitourinary disorders
Tubulointerstitial Nephritis
Symptoms and Signs of Tubulointerstitial Nephritis
Symptoms and signs of acute tubulointerstitial nephritis (ATIN) may be nonspecific and are often absent unless symptoms and signs of renal failure develop. Many patients develop polyuria and nocturia (due to a defect in urinary concentration and sodium reabsorption). ATIN symptom onset may be as long as several weeks after initial toxic exposure or as soon as 3 to 5 days after a second exposure; extremes in latency range from 1 day withrifampinto 18 months with a nonsteroidal anti-inflammatory drug (NSAID). Fever and urticarial rash are characteristic early manifestations of medication-induced ATIN, but the classically described triad of fever, rash, and eosinophilia is present in<10% of patients with medication-induced ATIN. Abdominal pain, weight loss, and bilateral renal enlargement (caused by interstitial edema) may also occur in ATIN and with fever may mistakenly suggest renal cancer or polycystic kidney disease. Peripheral edema and hypertension are uncommon unless renal failure occurs. Symptoms and signs are generally absent in chronic tubulointerstitial nephritis unless renal failure develops. Edema usually is not present, and blood pressure is normal or only mildly elevated in the early stages. Polyuria and nocturia may develop. 