Differentiating Kawasaki disease from urinary tract infection in febrile children with pyuria and C-reactive protein elevation

Abstract

Abstract Background Kawasaki disease (KD) is sometimes confused with urinary tract infection (UTI) because both can present with pyuria and C-reactive protein (CRP) elevation. The present study investigated the clinical and laboratory findings that can differentiate KD from UTI in febrile children with pyuria and CRP elevation. Methods Medical records were retrospectively reviewed for children with KD and those with UTI. The clinical and laboratory findings between the KD with pyuria group (n = 48) and the UTI group (n = 118) were compared. Results The KD with pyuria group had older age (P 70.0% of children in the KD with pyuria group, but < 20.0% of children in the UTI group possessed elevated liver enzymes (P < 0.001). On urinalysis, 40.7% of the UTI group had a positive nitrite test, but 0.0% of the KD with pyuria group had a positive nitrite test (P < 0.001). Conclusions Elevated liver enzymes are more specific to KD than to UTI, whereas a positive nitrite test is more specific to UTI than to KD. Our findings can be used as diagnostic clues to differentiate KD from UTI in febrile children with pyuria and CRP elevation.

Keywords

• Kawasaki disease
• Urinary tract infection
• Pyuria
• C-reactive protein