system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 67-year-old man comes to the emergency department for the evaluation of two episodes of red urine since this morning. He has no pain with urination. He reports lower back pain and fever. Six months ago, he was diagnosed with osteoarthritis of the right knee that he manages with 1–2 tablets of ibuprofen per day. He has smoked one pack of cigarettes daily for the past 45 years. He does not drink alcohol. His temperature is 38.5°C (101.3°F), pulse is 95/min, and blood pressure is 130/80 mm Hg. Physical examination shows faint, diffuse maculopapular rash, and bilateral flank pain. The remainder of the examination shows no abnormalities. Urinalysis shows:
Blood +3
Protein +1
RBC 10–12/hpf
RBC cast negative
Eosinophils numerous
Which of the following is the most likely diagnosis?"
assistant
Acute tubulointerstitial nephritis