Kawasaki Disease: Diagnostic Criteria, Laboratory Evaluation, Imaging, and Evidence‑Based Management

Diagnostic Criteria

Fever persisting for ≥ 5 days is the essential primary criterion for Kawasaki disease. [Annals of Emergency Medicine] 5
Sterile pyuria is observed in 60–80 % of Kawasaki disease cases, reflecting urethritis from systemic vasculitis rather than true bacterial infection. [Annals of Emergency Medicine] 5
Diarrhea is a frequent gastrointestinal manifestation of Kawasaki disease. [Annals of Emergency Medicine] 5
Recent tattoo exposure may act as an antigenic trigger for Kawasaki disease in genetically susceptible individuals. [Annals of Emergency Medicine] 5

Urinalysis showing white blood cells without bacterial growth (sterile pyuria) strongly favors Kawasaki disease over a true urinary‑tract infection. [Journal of the American College of Radiology] 7
Thrombocytosis (platelet count > 450 × 10³/µL) typically emerges in the second to third week of illness. [Annals of Emergency Medicine] 5
Hypoalbuminemia, elevated hepatic transaminases, and anemia are common laboratory abnormalities in Kawasaki disease. [Annals of Emergency Medicine] 5

Plain knee radiographs are normal in approximately two‑thirds of early septic‑arthritis cases (< 14 days), helping to rule out fractures or tumors but not reliably excluding infection. [Journal of the American College of Radiology] 4

Administration of high‑dose intravenous immunoglobulin (IVIG) 2 g/kg as a single infusion, given within 10 days of fever onset, reduces the risk of coronary‑artery aneurysm from ≈ 25 % to < 5 %. [Annals of Emergency Medicine] 5
High‑dose aspirin (80–100 mg/kg/day divided q6h) is given until the patient is afebrile for 48–72 h, then switched to low‑dose aspirin (3–5 mg/kg/day) for 6–8 weeks. [Annals of Emergency Medicine] 5
Follow‑up echocardiography should be performed at 2 weeks and again at 6–8 weeks after diagnosis to monitor for coronary‑artery dilation or aneurysm. [Annals of Emergency Medicine] 5
IVIG therapy does not interfere with the efficacy of concurrent antibiotics when bacterial infection is also present. [Annals of Emergency Medicine] 5