Differential Diagnosis for a 24-year-old Male with Fevers, Flank Pain, and Headache
Single Most Likely Diagnosis
- Pyelonephritis: Given the symptoms of fevers, right flank area pain, and slight elevation of creatinine and BUN, pyelonephritis is a strong consideration. The absence of renal stones and the presence of a solenoid (possibly referring to a renal or vascular structure) on the CT scan, along with clear urine, does not rule out this diagnosis, especially if the infection is not causing significant urinary abnormalities yet.
Other Likely Diagnoses
- Acute Interstitial Nephritis: This condition could explain the elevated creatinine and BUN, especially if the patient has recently started a new medication. However, the presence of fevers and flank pain might suggest an infectious or inflammatory cause.
- Viral Illness with Renal Involvement: Certain viral illnesses can cause renal impairment and could be considered, especially with the headache and fevers. The slight elevation in creatinine could be indicative of viral involvement affecting the kidneys.
Do Not Miss Diagnoses
- Sepsis of Renal Origin: Although the CBC is normal, sepsis can present subtly, and the source could be renal, especially with flank pain and fever. Missing sepsis could be catastrophic.
- Renal Infarction: This is a less common condition but could present with acute flank pain and renal dysfunction. It's crucial not to miss this diagnosis due to its potential for severe consequences if not promptly treated.
- Renal Vasculitis: Conditions like vasculitis could affect the kidneys and present with renal impairment and systemic symptoms like fever and headache.
Rare Diagnoses
- Renal Tuberculosis: Although rare in many parts of the world, renal TB can present with chronic or acute symptoms including flank pain, fever, and renal dysfunction.
- Renal Cell Carcinoma with Infection: A tumor could potentially become infected, leading to the patient's symptoms. However, this would be an uncommon presentation for renal cell carcinoma.
- Endocarditis with Renal Emboli: If the patient has a history of heart disease or intravenous drug use, endocarditis with septic emboli to the kidneys could be a rare but serious consideration.