A 2-year-old toddler is brought to the emergency department with persistent fever for 5 days and a rash. The nurse suspects Kawasaki disease. Which assessment finding would be MOST significant in supporting this diagnosis?

Key Diagnostic Criteria (AHA, 2017): Complete Kawasaki disease requires fever for at least 5 days plus four of five principal features. The question stem provides fever and rash, so the most significant additional finding is a new principal criterion.

• Bilateral Conjunctival Injection: Look for non-exudative, painless redness of both eyes without discharge. This is a highly specific and common criterion in the acute phase.
• Extremity Changes: Acute phase findings include erythema and edema of the hands and feet. Periungual peeling in the fingertips and toes is a later, convalescent-phase sign and would not be the most significant finding during initial evaluation.
• Oral Mucosal Changes: Assess for erythema, cracked lips, strawberry tongue, and pharyngeal injection without exudate.
• Cervical Lymphadenopathy: Typically unilateral, with at least one node measuring more than 1.5 cm. It is the least common of the five principal criteria.

Nursing Implications: Early recognition is critical to prevent coronary artery aneurysms. If Kawasaki disease is suspected, prepare the patient for intravenous immunoglobulin (IVIG) therapy and high-dose aspirin, along with baseline echocardiography. Monitor for cardiac complications and provide supportive care for fever and mucositis.