Pyuria is not always sterile in children with Kawasaki disease.

BACKGROUND: Although Kawasaki disease (KD) often presents with sterile pyuria, bacterial pyuria (urinary tract infection [UTI]) occasionally occurs.

METHODS: This was a retrospective cohort study of 285 children with KD diagnosed between 1995 and 2005. Among these patients, a total of 210 patients underwent routine urine tests and 75 children underwent urine culture tests. This study was conducted to investigate the incidence, clinical manifestations, management and outcome of KD with pyuria.

RESULTS: The incidence of pyuria was 29.5% (62/210). Among the 75 children undergoing urine culture tests, 34 had sterile pyuria (45.3%), eight had bacterial pyuria (10.7%), two had UTI without pyuria (2.7%) and 31 had neither pyuria nor UTI (41.3%). When pyuria was used as a predictor of KD with UTI, the positive and negative predictive values were 19% and 93.9%, respectively. There were no significant differences in demographic data, clinical presentations, laboratory results, duration of fever, ratio of resistant KD or risk level, except in the nitrite test, between both groups.

CONCLUSIONS: Pyuria was not always sterile in patients with KD. Although there was no different clinical phenotype or coronary outcome in KD patients with or without UTI, we suggest that UTI should be considered and evaluated in KD patients with pyuria, a positive nitrite test or a positive result of urine culture. If UTI is definitively diagnosed, the patient should be treated for a UTI as well as for KD and complete post-UTI work-up is recommended.