Overview
Acute pyelonephritis is an infection of the kidney parenchyma and renal pelvis, typically caused by bacteria ascending from the lower urinary tract. It is a form of acute uncomplicated or complicated urinary tract infection (UTI) characterized by systemic signs, most commonly fever 1.Diagnosis
Diagnosis is primarily clinical, based on symptoms such as flank pain, fever, and costovertebral angle tenderness, often accompanied by signs of lower UTI 1.
Urinalysis typically shows pyuria and bacteriuria. Urine culture and susceptibility testing are essential for identifying the causative pathogen and guiding antibiotic therapy 1.Management
Antibiotic therapy is the cornerstone of management.
Treatment durations are being evaluated, with evidence suggesting that shorter courses (5-7 days) may be non-inferior to longer courses (10-14 days) for pyelonephritis and febrile complicated UTIs 1.
Specific antibiotic choices and dosages depend on local resistance patterns and patient factors.Key Recommendations
For pyelonephritis or febrile complicated urinary tract infections, treatment durations of 5-7 days may be comparable to 10-14 days in terms of clinical success 1. (Evidence: Strong)References
1 Zahavi I, Kunwar D, Olchowski J, Dallasheh H, Paul M. Short vs. long antibiotic treatment for pyelonephritis and complicated urinary tract infections: a living systematic review and meta-analysis of randomized controlled trials. Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases 2025. link