Background: Coronary artery (CA) dilatation on echocardiography is a criterion for treatment with intravenous immunoglobulin for incomplete Kawasaki disease (KD). However, CA dimensions for febrile children are unknown. We compared CA dimensions in children with febrile illnesses other than KD to those of normal afebrile children and to KD patients.
Methods and results: We performed echocardiograms in 43 patients who met the following inclusion criteria: (1) age 3 months to 18 years, (2) daily fever >38°C for ≥96 hours, and (3) a diagnosis other than KD. These subjects had mean CA z scores greater than normative values (left main CA=0.66±0.75, P<0.001; right CA=0.28±0.81, P=0.03; left anterior descending CA=0.35±1.0, P=0.03). Maximum CA z score >2 was found in 2 subjects (osteomyelitis, Mycoplasma pneumonia). Among demographic and laboratory measures, only higher platelet count was associated with greater left anterior descending CA z scores (P=0.004) and maximum CA z score (P=0.03). Non-KD febrile subjects, compared with 144 KD patients, had smaller CA z scores (P=0.04, P<0.001, and P<0.001 for left main CA, right CA, and left anterior descending CA, respectively), and lower white blood cell count, erythrocyte sedimentation rate, and platelet count (all P<0.001). A maximum CA z score cutoff of 2.0 had specificity of 95% (95% confidence interval, 84%-99%) and sensitivity of 32% (95% confidence interval, 25%-41%) in distinguishing non-KD febrile from KD patients; for maximum CA z score of 2.5, specificity was 98% and sensitivity was 20%.
Conclusions: This pilot study found that mean CA dimensions in children with non-KD febrile illnesses are larger than those in normative afebrile subjects but smaller than dimensions in patients with KD. Future studies should augment the available data on CA dimensions in children with more severe febrile illnesses.