It is a bacterial urinary tract infection of the renal parenchyma and excretory tract intra-renal.
It is common in women.
There are two mechanisms of contamination:
Typically, the clinical picture associates signs of cystitis (voiding burns, urge to urinate and pollakiuria) with signs of renal parenchymal involvement:
fever, lower back pain radiating to the pubis and external genitalia.
Physical examination finds pain on palpation of the lumbar fossa.
Biological inflammatory syndrome: leukocytosis, high CRP.
Renal ultrasound is essential in the search for pyelocalicular dilation posing thus the diagnosis of acute obstructive pyelonephritis.
In the case of acute non-obstructive pyelonephritis, treatment is based on antibiotic therapy for 15 days associated with analgesic treatment and hyperdiuresis.
In obstructive forms the treatment is medico-surgical combining treatment antibiotic and urine drainage either by a double J catheter or by a percutaneous nephrostomy.