Urinary tract infection

This child has presented with an afebrile urinary tract infection (UTI). Afebrile UTIs are generally associated with cystitis whereas febrile UTIs are generally associated with pyelonephritis. Cystitis can be treated with oral antibiotics whereas pyelonephritis should be treated with intravenous antibiotics. In an infant, pyelonephritis may be associated with systemic signs such as vomiting, lethargy, sepsis and refusal of feeds. In this child, among the systemic signs only vomiting is present, hence evidence of pyelonephritis is still lacking. What is important is the USG finding of kidney sizes. Both kidneys are enlarged (average kidney size at 10 months should be around 5.5 cm). Enlarged kidneys may be due to hydronephrosis, polycystic kidney disease, isolated nephromegaly or due to infection i.e. pyelonephritis. Thus, in this child enlarged kidneys, vomiting are suggestive of pyelonephritis and the child should receive intravenous antibiotics. A DMSA scan done subsequently showed bilateral renal scars suggestive of acute pyelonephritis.