Aspirin has been used to treat KD for years, even before the treatment of IVIG [
27]. In the acute stage of KD, aspirin is administered at 80 to 100 mg/kg per day (30–50 mg/kg in Japan) [
25] with IVIG administration. Even though high-dose aspirin has significant anti-inflammatory and anti-platelet functions, it does not lower the incidence of CAL formation. Saulsbury et al. were the first to report that comparisons of two dosages of aspirin plus IVIG (2 g/kg) revealed no benefit in high-dose aspirin compared to low-dose aspirin in treating the acute stage of KD [
28]. In a previous study, we examine 851 KD patients from two medical centers in Taiwan (Chang Gung Memorial Hospital-Kaohsiung and Kaohsiung Veterans General Hospital) [
29]. The patients are divided into Group 1, with high-dose aspirin (
n = 305) and Group 2, without high-dose aspirin (
n = 546). No significant differences were found between Groups 1 and 2 with regard to gender (
p = 0.51), IVIG resistance rate (31/305 vs. 38/546,
p = 0.07), CAL formation rate (52/305 vs. 84/546,
p = 0.67), or total length of hospital stay (6.3 ± 0.2 days vs. 6.7 ± 0.2 days,
p = 0.13). These results indicate that high-dose aspirin in acute KD does not affect disease outcomes. Therefore, administering high-dose aspirin to treat KD appears to be unnecessary [
29]. Furthermore, high-dose aspirin decreased hemoglobin levels and affected the decrease of inflammation markers following IVIG administration [
29,
30]. A systemic meta-analysis also reported that both low-dose aspirin and high-dose aspirin have a similar incidence of CAL development in KD patients [
31]. All of these findings suggest that high-dose aspirin treatment may not be correlated with higher benefits with regard to CAL formation, IVIG resistance, and shorter hospital stays.
In conclusion, various retrospective studies have shown that high-dose aspirin does not offer any significant benefits in the acute stage of KD. However, no randomized controlled trial regarding the use of high-dose aspirin in the acute stage of KD has yet been done. Therefore, we have initiated this randomized controlled trial to determine whether high-dose aspirin is actually necessary for treating the acute stage of KD.