Pyelonephritis vs. Renal Colic

To distinguish Pyelo (i.e. Infection) from a Kidney Stone:

  • Fever strongly suggests Pyelo
  • Flank &/or CVA tenderness suggest Pyelo
  • Very abrupt onset suggests Stone
  • Recurrent wave-like paroxysms of pain, lasting around 20 minutes, suggest Stone.
  • Kidney Stone pain radiates to groin / genitals
  • History of prior episodes suggests Stone

Findings on Dipstick Urinalysis:

Leukocyte Esterase:
  • Negative = Definitely NOT Pyelo
  • Positive = could be either Pyelo or Stone
  • Positive = Likely Pyelo (OR very Contaminated Specimen)
  • Negative = Could be Pyelo with low colony count, OR no UTI
  • Negative = speaks against Stone (not for sure, though)
  • Positive = Stone (if leukocyte esterase is Neg) OR menses
Specific Gravity:
  • Very Low (<1.005) = suspect false-negative leukocyte esterase / nitrites
pH:  >7.0 suggests Proteus or Klebsiella UTI
  • maybe with enormous struvite staghorn stone

See posting Abdominal Pain – 2.