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 to identify leukocytosis with neutrophilia and normocytic normochromic anaemia, which are common inflammatory markers in Kawasaki Disease NICE NG143 Dimitriades et al. 2014.
• Elevated inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are typically present and support the diagnosis NICE NG143 Rashid et al. 2014.
• Elevated liver enzymes (transaminases) and hypoalbuminaemia may be observed, reflecting systemic inflammation and hepatic involvement Dimitriades et al. 2014.
• Urinalysis may show sterile pyuria, which is a supportive but nonspecific finding NICE NG143 Rashid et al. 2014.
• Platelet count is often normal or low in the acute phase but typically rises (thrombocytosis) in the subacute phase, which can aid in diagnosis and monitoring NICE NG143 Dimitriades et al. 2014.
• Additional emerging biomarkers such as noncoding RNAs have been investigated for diagnostic significance, but these are not yet standard clinical tests Zhong et al. 2022.

In summary, the diagnosis of Kawasaki Disease is supported by laboratory evidence of systemic inflammation (raised CRP, ESR), haematological changes (leukocytosis, thrombocytosis), and exclusion of other causes, in conjunction with clinical criteria NICE NG143 Dimitriades et al. 2014Rashid et al. 2014Zhong et al. 2022.