Pyelonephritis occurs secondary to an inflammatory process involving the kidney and renal pelvis. It refers to chronic interstitial nephritis believed to have resulted from a bacterial infection of the kidney.

Bacterial infections result in pyelonephritis. However, several noninfectious processes may result in interstitial nephritis that is indistinguishable from chronic pyelonephritis.

This condition causes an abrupt onset of chills, fever and dull pain in the flank over either or both kidneys. Tenderness is experienced on palpation. In addition, the patient often encounters pyuria; and urgency, burning, and frequency of urination, which are signs of cystitis. It is reported that 8% to 10% of patients with urinary tract infections (UTI) have pyelonephritis.

Diagnosis of pyelonephritis is generally based on finding bacteria in the urine by gram staining in the presence of the above signs and symptoms. In most cases, the clinical features and microscopic findings in urine provide the diagnosis. History of recurrent UTI and acute pyelonephritis is helpful in the diagnosis. Blood tests sometimes show an elevated creatinine and blood urea nitrogen (BUN) levels. Blood cultures are indicated for patients with fever, low blood pressure, or acute confusion.

If renal pelvis or ureteral obstruction due to a calculus is suspected, ultrasound or radioisotope scanning may be performed.
 

Therapy includes identification and removal of the cause, increasing resistance to infection, and bedrest. It is recommended that substances that can irritate the kidney, e.g., alcohol and certain drugs, be avoided. Heat is applied to the lower back (flanks), and antipyretics and antibiotics are given. Surgery may be indicated if obstruction occurs.

Patients experiencing uncomplicated pyelonephritis who receive appropriate treatment usually experience a complete resolution of symptoms. Uncomplicated conditions rarely advance to chronic renal disease. However, patients with previous renal damage may experience a permanent reduction in renal function. Patients who develop septicemia have a poor prognosis.

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See 38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• Rate as renal dysfunction or urinary tract infection, whichever is predominant.

• This disease shall be granted service connection although not otherwise established as incurred in or aggravated by service if manifested to a compensable degree within the applicable time limits under 38 CFR 3.307 following service in a period of war or following peacetime service on or after January 1, 1947, provided the rebuttable presumption provisions of 38 CFR 3.307 are also satisfied [ 38 CFR 3.309.  [Disease subject to presumptive service connection], 38 CFR 3.309(a) [chronic disease].

• The new criteria for the Genitourinary Disease and Conditions body system became effective November 14, 2021.  Review both current and historic criteria prior to any reduction for disabilities established before that date.  38 CFR 3.951(a)

• When evaluating any claim involving loss or loss of use of one or more creative organs, refer to 38 CFR 3.350 of this chapter to determine whether the Veteran may be entitled to special monthly compensation. Footnotes in the schedule indicate conditions which potentially establish entitlement to special monthly compensation; however, there are other conditions in this section which under certain circumstances also establish entitlement to special monthly compensation.