Differential Diagnosis
- Single most likely diagnosis
- Pyelonephritis: The patient presents with left flank pain, elevated CRP (23.4), and a urinalysis showing many bacteria and a high WBC count (50), which are all indicative of a urinary tract infection involving the kidney. The CT finding of nonspecific edema in the proximal right renal collecting system could be consistent with pyelitis or an infection of the renal collecting system.
- Other Likely diagnoses
- Nephrolithiasis (Kidney Stones): The CT mention of considerations including a passed calculus, along with the patient's flank pain, could suggest that the patient has or recently had a kidney stone. However, the presence of many bacteria in the urine leans more towards an infectious process.
- Acute Uncomplicated Cystitis: Although the symptoms and lab results more strongly suggest an upper urinary tract infection, cystitis (infection of the bladder) cannot be ruled out entirely, especially given the urinalysis results.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Sepsis: Given the elevated WBC count (13.8) and CRP (23.4), along with the presence of a significant infection (as indicated by the urinalysis), there is a risk of the infection progressing to sepsis, a potentially life-threatening condition.
- Obstructive Uropathy: If a kidney stone or other obstruction is present and not promptly addressed, it could lead to serious complications, including renal failure.
- Emphysematous Pyelonephritis: A rare but serious infection of the kidney where gas is formed in the kidney tissue, often associated with diabetes or urinary obstruction. It's a medical emergency.
- Rare diagnoses
- Xanthogranulomatous Pyelonephritis: A rare form of chronic pyelonephritis that involves cellular infiltration and destruction of the renal tissue, often associated with long-standing urinary tract obstruction and infection.
- Tuberculosis of the Kidney: Although less common, especially in regions with good healthcare, renal tuberculosis could present with similar symptoms, including flank pain and abnormal urinalysis. However, the presence of many bacteria in the urine would typically point more towards a bacterial infection rather than TB.