Risk factors for Kawasaki disease-associated coronary abnormalities differ depending on age.

INTRODUCTION: The clinical manifestations and risk factors for developing coronary artery abnormalities (CAA) in Kawasaki disease (KD) might differ depending on age. MATERIALS AND METHODS: From January 2001 to July 2007, 161 patients with an age younger than 1 year (younger group) and 60 patients with an age older than 5 years (older group) were diagnosed with KD at the Korea University Medical Center. Their medical records were reviewed retrospectively and the two groups were compared in terms of a number of variables commonly associated with the development of CAA, including clinical manifestations and laboratory findings. RESULTS: While the overall incidence of KD-associated CAA in our hospital was 6.7%, CAA developed in 20 (12.4%) of the younger group and ten (16.7%) of the older group, respectively. The CAA (+) cases of the younger group had a longer duration of total fever (9.1 +/- 3.3 vs 6.3 +/- 1.9 days, p = 0.002) and showed fewer diagnostic symptoms (3.0 +/- 1.2 vs 4.3 +/- 1.1, p < 0.001) than the CAA (-) cases. The CAA (+) cases of the older group had a longer duration of total fever (14.1 +/- 10.4 vs 6.5 +/- 1.9 days, p = 0.045), especially with respect to post-intravenous gamma globulin (IVGG) fever (7.9 +/- 9.6 vs 1.1 +/- 0.8 days, p = 0.052), and had higher total white blood cell counts, erythrocyte sedimentation rates, C-reactive protein levels, total bilirubin levels, and Harada scores and lower serum albumin and sodium levels than the CAA (-) cases. Multivariable logistic regression analysis revealed that the factors that were associated significantly with the development of CAA were the number of total symptoms (OR = 0.494, 95% confidence interval (CI) = 0.281-0.871, p = 0.015) in the younger group and the duration of post-IVGG fever (OR = 1.958, 95% CI = 1.098-3.492, p = 0.023) and the Harada score (OR = 3.455, 95% CI = 1.012-11.796, p = 0.048) in the older group. CONCLUSION: Incomplete clinical manifestations in the younger group and IVGG nonresponsiveness in the older group are associated with the development of KD-associated CAA. These age-specific characteristics could aid the customization of the diagnostic and therapeutic strategies of KD, thereby helping to improve the outcome of this disease.

Incomplete Kawasaki disease in patients younger than 1 year of age: a possible inherent risk factor.

Kawasaki disease (KD) patients younger than 1 year of age are at especially high risk of developing coronary artery abnormalities (CAA). To define the clinical characteristics of this group, as well as the risk factors predisposing them to CAA, we reviewed the medical records of 136 KD patients younger than 1 year of age who were treated at the Korea University Medical Center from January 2001 to July 2006. Of these patients, 16 developed CAA (11.8%). The CAA(+) group had a longer duration of total fever than the CAA(-) group (9.1+/-3.7 days vs. 6.3+/-2.0 days, p=0.011), but did not differ in the duration of pre- and post-intravenous gamma-globulin (IVGG) fever. The CAA(+) group had fewer diagnostic symptoms than the CAA(-) group (2.7+/-1.1 vs. 4.3+/-1.2, p<0.001). Of the hematological findings, the CAA(+) group only differed from the CAA(-) group in having significantly higher total white blood cell (19.2+/-6.0 vs. 14.7+/-4.7 K/mm(3), p=0.007) and platelet (462.9+/-101.0 vs. 383.6+/-121.1 K/mm(3), p=0.014) levels. Multivariable logistic regression analysis showed that the only factors which were significantly associated with the development of CAA were the total number of symptoms (OR=0.493, 95% CI=0.293-0.829, p=0.007) and the duration of total fever (OR=1.405, 95% CI=1.092-1.808, p=0.008). Conclusively, incomplete clinical manifestations and a longer duration of total fever are significantly associated with the development of CAA in KD patients younger than 1 year of age. Therefore, these patients should be monitored for incomplete KD, especially if unexplained fever continues, and treatment to shorten the duration of total fever should be initiated.