The present study was performed to evaluate the clinical symptoms and cardiovascular complications in patients with typical and atypical Kawasaki disease (KD). This retrospective study was conducted on the medical records of 176 patients with KD for three years. The study population was divided into two groups of typical and atypical based on the KD clinical criteria. The two groups were compared in terms of demographic data, clinical symptoms, cardiac lesions, and laboratory markers. Based on the diagnostic criteria, 105 (60%) and 71 (40%) patients were diagnosed with typical and atypical KD, respectively. The mean age of the typical patients (38.16 months) was higher than that of the atypical group (24.03 months) at the time of diagnosis (p < 0.05). The results revealed no significant difference between the two groups regarding the seasonal distribution of KD onset (p = 0.422). However, the most common season for the diagnosis of the disease was spring, followed by winter. There was no significant difference between the two groups in terms of fever duration (p = 0.39). Furthermore, vomiting was more common in the atypical patients than in the typical group (p = 0.017). In terms of the cardiac lesions, ectasia (p = 0.005) and lack of tapering of the distal coronary vessels (p = 0.015) were more frequently detected in the atypical group than in the typical group. Considering the laboratory findings, thrombocytosis (p = 0.010) and anemia (p = 0.048) were more common in the atypical group, compared to those in the typical group. On the other hand, the typical group had a higher serum alanine aminotransferase level (adjusted for age) (p = 0.012) and Hyponatremia (serum sodium concentration ≤130 mmol/L) (p = 0.034). Based on the findings of the current study, the fever duration from onset to diagnosis was slightly more in atypical KD patients than in the typical group, but not statistically significant, possibly due to more timely diagnosis of atypical KD. There was no difference in coronary aneurysm between the two groups at the time of diagnosis. The atypical group had a higher frequency of coronary ectasia and lack of tapering, indicating cardiac involvement. Consequently, these conditions should be given more attention in the atypical patients. Furthermore, the higher frequency of anemia and thrombocytosis in the atypical patients can be useful for diagnosis of this kind of KD.
Keywords: Kawasaki disease; atypical; cardiac lesions; typical.