Incidence and Clinical Significance of Retropharyngeal Edema in Node-first Presentation of Kawasaki Disease

BACKGROUND: Diagnosing node-first Kawasaki disease (NFKD), which initially presents with fever and cervical lymphadenopathy, is challenging, particularly during the early stages of the disease. Although case reports have described retropharyngeal edema (RPE) on contrast-enhanced neck computed tomography (CT) in NFKD, its prevalence and diagnostic value remain unclear. We sought to clarify the clinical characteristics of NFKD and evaluate the significance of RPE. METHODS: We retrospectively reviewed children diagnosed with Kawasaki disease (KD) at Nagoya Memorial Hospital between January 2023 and March 2025. Among patients with NFKD who underwent CT, we calculated the proportion exhibiting RPE. We compared demographic, laboratory and CT findings between patients with NFKD and those with non-NFKD. RESULTS: Among 99 hospitalized patients with KD, 30 had NFKD, and 57 had non-NFKD; patients who did not receive intravenous immunoglobulin or had recurrent KD were excluded. RPE was observed in 68.4% of NFKD cases undergoing CT. Patients with NFKD were likely to be older and exhibited less conjunctival injection and skin manifestations. Rates of intravenous immunoglobulin nonresponse and coronary artery lesions did not differ between groups. Among the 11 non-KD patients with fever and cervical lymphadenopathy, RPE was not detected in any condition except for peritonsillar abscess. CONCLUSIONS: RPE on neck CT may aid in the diagnosis of NFKD, particularly in older children presenting with fever and cervical lymphadenopathy but lacking conjunctival or skin findings. Larger multicenter studies are warranted to confirm the diagnostic value of RPE in the early identification of NFKD.