Quando la febbre non ha una chiara localizzazione: pensa anche alla nefrite focale acuta

Acute lobar nephronia (ALN) is a non-suppurative focal form of acute bacterial infection, generally affecting one or more renal lobules. In the spectrum of upper urinary tract infection ALN is consid-ered a midpoint between uncomplicated pyelonephritis and intrarenal abscess. This condition may be difficult to recognize due to the lack of specific symptoms and laboratory findings. The reported incidence of ALN has increased as a result of advancements in non-invasive imaging techniques such as renal ultrasonography. Computed tomography scanning is the diagnostic gold standard for ALN, but magnetic resonance imagining (MRI) should be considered to limit irradiation and be-cause of its high sensitivity in detecting inflammatory changes in the renal parenchyma. The diag-nosis is relevant since initial intravenous antibiotic therapy and overall length of treatment, usually 3 weeks, are longer respect to those for uncomplicated acute pyelonephritis. The present paper de-scribes the case of a 4-year-old girl with septic fever, sick appearance, elevation of inflammatory indexes with negative blood and urine cultures and non-specific abdominal ultrasonography in which a detailed evaluation of MRI led to the diagnosis of acute lobar nephronia.