What laboratory investigations are recommended to support the diagnosis of Kawasaki Disease?

Laboratory investigations recommended to support the diagnosis of Kawasaki Disease include:

• Full blood count (FBC) to detect leukocytosis with neutrophilia and thrombocytosis, which typically develops in the subacute phase.
• Inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are usually elevated, reflecting systemic inflammation.
• Elevated liver enzymes and hypoalbuminaemia may be present, supporting systemic involvement.
• Urinalysis may show sterile pyuria, which can be a supportive finding.
• Additional tests such as serum sodium (often low) and elevated brain natriuretic peptide (BNP) or N-terminal pro-BNP can assist in assessing cardiac involvement.
• Blood cultures and other infection screens are important to exclude alternative diagnoses.

These investigations are primarily supportive, as Kawasaki Disease remains a clinical diagnosis based on characteristic signs and symptoms. Recent literature also highlights emerging biomarkers such as noncoding RNAs that may improve diagnostic accuracy in the future, but these are not yet standard in clinical practice (Dimitriades et al., 2014; Zhong et al., 2022; Ahn, 2024) ¹.