Background: Among typical patients with Kawasaki disease (KD), a few KD patients present with only fever and cervical lymphadenopathy at admission (KDL). These patients have a significant risk for misdiagnosis, delay in treatment for KD, and development of coronary artery abnormalities. Therefore, the development of an easy tool for early diagnosis in these patients is desirable.
Methods and results: Patients who presented with only fever and cervical lymphadenopathy at admission were studied. Of these, 14 patients were eventually diagnosed with KD (KDL) and 24 patients were successfully treated using antibiotics (control). KDL patients were significantly older than control patients (P > 0.022). Among the laboratory findings, neutrophil counts (P > 0.003), C-reactive protein (CRP; P < 0.001), and aspartate aminotransferase (AST; P > 0.018) were significantly different between the groups. To discriminate KDL patients from controls, cut-off points of the aforementioned parameters (KDL indices) were determined using the receiver operating characteristic curves in order to maximize sensitivity and accuracy (age, 5.0 years; neutrophil counts, 10,000 /microL; CRP, 7.0 mg/dL; AST, 30 IU/L). One point was assigned if a subject exceeded the cut-off point in a KDL index. If a patient with three or four KDL indices was considered to have KD, the sensitivity was 78% and the specificity 100%. None of the patients with one or zero KDL index developed KD.
Conclusions: KDL indices may be helpful in discriminating KDL from lymphadenitis at admission. It is important to monitor the symptoms of KD in a patient with three or four KDL indices at admission.