What are the key clinical features to consider when diagnosing Kawasaki Disease in children?

The key clinical features to consider when diagnosing Kawasaki Disease (KD) in children include a persistent fever lasting at least 5 days, accompanied by at least four of the following principal features:

• Conjunctival injection: bilateral, non-purulent conjunctivitis without exudate.
• Oral mucosal changes: such as erythema, cracked lips, strawberry tongue, and diffuse redness of the oropharynx.
• Polymorphous rash: a widespread rash that can vary in appearance.
• Extremity changes: including erythema and swelling of the hands and feet in the acute phase, followed by periungual desquamation in the subacute phase.
• Cervical lymphadenopathy: typically unilateral, with at least one lymph node >1.5 cm in diameter.

Additional clinical features that may support the diagnosis include irritability, arthritis or arthralgia, and gastrointestinal symptoms. Laboratory findings often show elevated inflammatory markers, but these are supportive rather than diagnostic.

It is important to note that incomplete or atypical presentations can occur, especially in infants and older children, where not all classic criteria are met but the risk of coronary artery involvement remains significant. Therefore, clinical suspicion should remain high in any child with prolonged unexplained fever and some features of KD.

This integrated approach aligns with UK clinical guidelines emphasizing the principal diagnostic criteria and the importance of fever duration ¹, while contemporary literature highlights the broader spectrum of clinical manifestations and the need for vigilance in atypical cases (Bayers et al., 2013; Lee et al., 2022; Day-Lewis et al., 2024).