RESUMEN
Background: urinary tract infection is one of the most popular infections in childhood, and pyelonephritis with delayed and improper treatment results in renal scarving
Objective: the present study was done for evaluation of the most important parameters in differentiating pyelonephritis from cystitis
Methods: this cross sectional study was done in Mofid children's hospital from 1999 for 3 years in about 96 children with the first U.T.I. Acute pyelowphritis diagnosed by D.M.S.A. scan. Parameters such as fever, E.S.R., C.R.P. and W.B.C. were searched in differentiation between these two diseases
Findings: 75% of patients were younger than 5 years old, and the most common symptoms were dysuria or urinary frequency, urinary incontinence and flank pain. The most isolated germ, was E.coli. C.R.P. [qualitative] was positive in 40 cases of pyelonephritis and 6 of cystitis. Fever, E.S.R., and W.B.C. are not important statistical parameters in differentiation between pyelonephritis and cystitis
Conclusion: C.R.P. is the most valuable parameter in differentiating pyelonephritis from cystitis, that has low sensitivity and specificity comparing D.M.S.A. scan