Symptoms of cystitis may or may not be present. Besides fever, tachycardia, marked tenderness of deep pressure in one or both costovertebral areas or on deep abdominal palpation. In some patients, signs and symptoms of gram-negative sepsis predominate. Most patients have significant leukocytosis, pyuria with leukocyte casts in the urine, and bacteria on a gram stain of unspun urine. Hematuria may be present.
Symptoms usually subside over a few days.
Pathophysiology Acute pyelonephritis is a bacterial infection of the kidney with acute inflammation of the pyelocaliceal lining and renal parenchyma centrifugally along medullary rays. The etiology is from infected urine in the lower tract. Women are much more commonly affected than men. The typical age is 15-40. Predisposing factors include reflux, obstruction, calculi, altered bladder function, altered host resistance, pregnancy and congenital urinary tract abnormalities.