Case history
Case history
A 67-year-old man has been receiving amoxicillin treatment for bronchitis for 2 weeks. He develops a macular rash on his neck, torso, and back. The amoxicillin is therefore changed to cefalexin for an additional 7 days. The rash resolves, but he returns complaining of fatigue and a low-grade temperature that has persisted despite the resolution of bronchitis. He has not noticed any changes in his urine output. He has a history of hypertension, hyperlipidaemia, a previous myocardial infarction (6 years ago), and symptoms suggestive of gastric reflux. There is no history of renal disease. He has been on a stable regimen of lisinopril, metoprolol, simvastatin, and omeprazole. Physical examination reveals a blood pressure of 140/85 mmHg, pulse 68 bpm regular, temperature 37.8°C (100°F), and respirations of 16/minute. Examination is normal. Blood test results show an elevated serum creatinine value (177 micromol/L [2.0 mg/dL] from a level of 80 micromol/L [0.9 mg/dL] 3 months ago).
Other presentations
The loss of kidney function may be acute (within 7 days), characterised by acute kidney injury (AKI), in about half the cases, and sub-acute (between 7 and 90 days), characterised by acute kidney disease (AKD), in the other half.[2] Classic allergic features such as fever, rash, and eosinophilia are noted in <10% of people with acute interstitial nephritis (AIN).[3]
Patients with NSAID-induced AIN may present with AKI accompanied by oedema secondary to concurrent nephrotic syndrome.[1]
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