A 30-year-old woman presents to the outpatient clinic with a two-week history of fatigue, generalized malaise, and intermittent fever. She also reports recent onset of a rash on her trunk and extremities, along with a decrease in urine output and dark-coloured urine. She has no significant past medical history but mentions starting a new medication, an antibiotic, for a urinary tract infection (UTI) about three weeks ago.

On examination, she appears fatigued and has a temperature of 100.5°F (38.1°C). There is a maculopapular rash noted on her trunk and arms, and her blood pressure is slightly elevated at 130/85 mmHg. Laboratory tests reveal an elevated serum creatinine level of 2.2 mg/dL, indicating acute kidney injury, and a urinalysis shows significant proteinuria, haematuria, and the presence of eosinophils. A kidney biopsy is performed, confirming the diagnosis of acute interstitial nephritis (AIN), likely related to the recent antibiotic use.

The patient is started on corticosteroids to reduce the inflammatory response and is advised to discontinue the offending medication. She is closely monitored for improvement in her kidney function and symptoms. Lifestyle modifications, including adequate hydration, are recommended, and follow-up appointments are scheduled to assess her recovery and renal function.