Bland Urine Sediment in a Child with Acute Kidney Injury.

Tubulointerstitial nephritis (TIN) or acute interstitial nephritis (AIN) is a renal lesion characterized by inflammatory infiltrate limited to the renal interstitium and tubules. Three-fourths of the cases are drug induced, other causes being systemic and autoimmune diseases, and infections. Various drugs have been implicated, the most common being antibiotics such as β-lactams. Cephalosporins causing AIN have been reported uncommonly, particularly in children. Although renal biopsy confirms the diagnosis, urinalysis provides pertinent diagnostic clues against the backdrop of the clinico-laboratory profile. The presence of white blood cells, white cell casts, and red blood cells in urine sediment have been described in literature. However, a relatively normal urinalysis may be present in some cases and may pose a diagnostic challenge. We present a case of ceftriaxone-induced AIN in a child with bland urine sediment at initial presentation. To the best of our knowledge, this is the first report of ceftriaxone-induced AIN in the pediatric age group.