Kawasaki disease in Sweden: incidence and clinical features.

The incidence and clinical pattern of patients with Kawasaki disease in Sweden and the outcome of treatment with i.v. immunoglobulin (Sandoglobulin) and aspirin were examined in a national prospective study over a 2-year period. Cases not referred to the study were identified by inquiry. Ninety-nine children were diagnosed as having Kawasaki disease. The annual incidence rate was calculated to be 2.9 per 100,000 in children younger than 16 years of age and 6.2 per 100,000 in children younger than 5 years of age. The median age of our patients was 2.2 years and the male-to-female ratio was 2.3:1. Cardiac ultrasonography revealed abnormalities in 33% of all patients, and 14% of cases in the prospective study had pronounced abnormalities. In most cases (91%) treatment had a prompt effect on fever and morbidity in general, and side effects were mild. Two infants, identified from the inquiry, died from rupture of an aneurysm in the coronary artery in the acute phase of the disease. The risk of cardiac involvement is obvious and emphasizes the importance of early diagnosis and treatment.