Inflammatory processes in Kawasaki disease reach their peak at the sixth day of fever onset: laboratory profiles according to duration of fever.

We evaluated the inflammatory indices according to the fever duration in children with Kawasaki disease (KD), and determined duration when the inflammatory processes in KD reach their peak. Children with KD (n=152) were classified into 7 groups according to fever duration: at the third day or earlier (n=20), fourth (n=33), fifth (n=46), sixth (n=15), seventh (n=15), eighth (n=9), and at the ninth day or later after fever onset (n=14). The levels of various laboratory indices were determined 3 times: before, 24 hr and 7 days after intravenous immunoglobulin administration (2 g/kg). WBC and neurophil counts, and C-reactive protein level were the highest at the sixth day. Levels of hemoglobin, albumin, and high density lipoprotein cholestrol were the lowest at the sixth day. Although these indices were not significant statistically between groups, the indices showed either bell-shaped or U-shaped distribution of which peak or trench were at the sixth day. These findings showed that the inflammatory processes in KD reach peak on the sixth day of fever onset. This finding is important because a higher single-dose intravenous immunoglobulin treatment before the peak day may help reduce the coronary artery lesions in KD.