Fever of Unknown Origin

Learning points from today's case report:

1.  FUO may be due to infections, non-infectious inflammatory disorders (i.e. vasculitis, connective tissue diseases, and granulomatous disorders), malignancies, and many other disorders.  The cause of many FUOs are ultimately never identified.

2.  "Striated nephrogram" is a radiographic pattern of contrast on CT scans of the kidney of linear bands of contrast extending from the medulla of the kidney towards the cortex.  DDx includes ureteric obstruction, acute pyelonephritis, contusion, renal vein thrombosis, tubular obstruction, hypotension, or autosomal recessive polycystic kidney disease.

"Striated Nephrogram" - notice the striped pattern on the kidneys. Reference: radiopaedia.org

"Striated Nephrogram" - notice the striped pattern on the kidneys.
Reference: radiopaedia.org

3.  IDSA Guidelines re Pyelonephritis:
    -First line options: Fluoroquinolone x 7 days or Trimethoprim-Sulfamethoxazole x 14 days
    -If first line options cannot be used, a 10-14 day course of oral B-lactams are acceptable based on expert opinion