CRP and arthritic joint disease: The median serum concentration of CRP during the acute phase before IVIG, after treatment for the acute phase of KD, during active arthritis, and during arthritis remission was 9.3 mg/dL (IQR, 7.3–13.8 mg/dL), 0.7 mg/dL (IQR, 0.3–1.4 mg/dL), 2.4 mg/dL (IQR, 1.1–4.8 mg/dL), and 0.03 mg/dL (IQR, 0.02–0.10 mg/dL), respectively.